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Essay On Morality Is Moral Only When Voluntary

1. Introduction

1.1 The puzzle of Locke's moral philosophy

There are two main stumbling blocks to the study of Locke's moral philosophy. The first regards the singular lack of attention the subject receives in Locke's most important and influential published works; not only did Locke never publish a work devoted to moral philosophy, but he dedicates little space to its discussion in the works he did publish. The traditional moral concept of natural law arises in Locke's Two Treatises of Government (1690) serving as a major plank in his argument regarding the basis for civil law and the protection of individual liberty, but he does not go into any detail regarding how we come to know natural law nor how we might be obligated, or even motivated, to obey it. In his Essay Concerning Human Understanding (first edition 1690; fourth edition 1700, hereafter referred to as the Essay) Locke spends little time discussing morality, and what he does provide in the way of a moral epistemology seems underdeveloped, offering, at best, the suggestion of what a moral system might look like rather than a fully-realized positive moral position. This brings us to the second major stumbling block: What Locke does provide us by way of moral theory in these works is diffuse, with the air of being what J.B. Schneewind has characterized as “brief, scattered and sometimes puzzling” (Schneewind 1994, 200). This is not to suggest that Locke says nothing specific or concrete about morality. Locke makes references, throughout his works, to morality and moral obligation. However, two quite distinct positions on morality seem to emerge from Locke's works and it is this dichotomous aspect of Locke's view that has generated the greatest degree of controversy. The first is a natural law position, which Locke refers to in the Essay, but which finds its clearest articulation in an early work from the 1660s, entitled Essays on the Law of Nature. In this work, we find Locke espousing a fairly traditional rationalistic natural law position, which consists broadly in the following three propositions: first, that moral rules are founded on divine, universal and absolute laws; second, that these divine moral laws are discernible by human reason; and third, that by dint of their divine authorship these rules are obligatory and rationally discernible as such. On the other hand, Locke also espouses a hedonistic moral theory, in evidence in his early work, but developed most fully in the Essay. This latter view holds that all goods and evils reduce to specific kinds of pleasures and pains. The emphasis here is on sanctions, and how rewards and punishments serve to provide morality with its normative force. Both elements find their way into Locke's published works, and, as a result, Locke seems to be holding what seem to be incommensurable views. The trick for Locke scholars has been to figure out how, or even if, they can be made to cohere. The question is not easily settled by looking to Locke's unpublished works, either, since Locke also seems to hold a natural law view at some times and a hedonistic view at others.

One might conclude, with J.B. Schneewind, among others, that Locke's attempts at constructing a morality were unsuccessful. Schneewind does not mince words when he writes the following: “Locke's failures are sometimes as significant as his successes. His views on morality are a case in point” (Schneewind 1994, 199). Schneewind argues that the two strands of Locke's moral theory are irreconcilable, and that this is a fact Locke must have realized. This view is indeed an apt representation of the frustration many readers have felt with Locke's moral theory. Locke's eighteenth-century apologist, Catharine Trotter Cockburn thought Locke provided a promising, but incomplete, starting point for a positive moral system, imploring, in her work “A Defense of Mr. Locke's Essay of Human Understanding,”

I wish, Sir, you may only find it enough worth your notice, to incite you to show the world, how far it falls short of doing justice to your principles; which you may do without interrupting the great business of your life, by a work, that will be an universal benefit, and which you have given the world some right to exact of you. Who is there so capable of pursuing to a demonstration those reflections on the grounds of morality, which you have already made? (Cockburn 1702, 36)

Locke's friend William Molyneux similarly implored Locke to make good on the promise found in the Essay. In a letter written to Locke on September 16th, 1693, Molyneux presses Locke to work on a moral treatise once he has finished editing the second edition of his Essay, writing as follows:

I am very sensible how closely you are engaged, till you have discharged this Work off your Hands; and therefore will not venture, till it be over, to press you again to what you have promis'd in the Business of Man's Life, Morality. (Locke 1742, 53)

Several months later, in December of the same year, Molyneux concludes a letter by asking Locke about what other projects he currently has on the go “amongst which, I hope you will not forget your Thoughts on Morality” (Locke 1742, 54).

Locke never did produce such a work, and we might well wonder if he himself ever considered the project a “failure”. There is no doubt that morality was of central importance to Locke, a fact we can discern from the Essay itself; there are two important features of the Essay that serve to enlighten us regarding the significance of this work in the development of Locke's moral views. First of all, morality seems to have inspired Locke to write the Essay in the first place. In recounting his original inclination to embark on the project, he recalls a discussion with “five or six friends”, at which they discoursed “on a Subject very remote from this” (Locke 1700, 7). According to Locke, the discussion eventually hit a standstill, at which point it was agreed that in order to settle the issue at hand it would first be necessary to, as Locke puts it, “examine our own Abilities, and see, what Objects our Understandings were, or were not fitted to deal with” (Locke 1700, 7). This was, he explains, his first entrance into the problems that inspired the Essay itself. But, what is most interesting for our purposes is just what the remote subject was that first got Locke and his friends thinking about fundamental questions of epistemology. James Tyrell, one of those who attended that evening, is a source of enlightenment on this matter—he later recalled that the discussion concerned morality and revealed religion. But, Locke himself refers to the subjects they discussed that fateful evening as ‘very remote’ from the matters of the Essay. That may well be, but it is also true that Locke, in the Essay, identifies morality as a central feature of human intellectual and practical life, which brings us to the second important fact about Locke's view of morality. Locke writes, in the Essay, that “Morality is the proper Science, and Business of Mankind in general” (Essay, 4.12.11; these number are, book, chapter and section, respectively, from Locke's Essay). For a book aiming to set out the limits and extent of human knowledge, this comes as no small claim. We must, Locke writes, “know our own Strength” (Essay, 1.1.6) and turn our attention to those areas in which we can have certainty, i.e., “those [things] which concern our Conduct” (Essay, 1.1.6). The amount of attention given to the question of morality itself would seem to belie its primacy for Locke. The Essay is certainly not intended as a work of moral philosophy; it is a work of epistemology, laying the foundations for knowledge. However, a very big part of the programme involves identifying what true knowledge is and what it is we as humans can have knowledge about, and morality is accorded a distinctive and fairly exclusive status in Locke's epistemology as one of “the Sciences capable of Demonstration” (Essay, 4.3.18). The only other area of inquiry accorded this status is mathematics; clearly, for Locke, morality represents a unique and defining aspect of what it means to be human. We have to conclude, then, that the Essay is strongly motivated by an interest in establishing the groundwork for moral reasoning. However, while morality clearly has a position of the highest regard in his epistemological system, his promise of a demonstrable moral science is never realized here, or in later works.

It seems we can safely say that the subject of morality was a weighty one for Locke. However, just what Locke takes morality to involve is substantially more complicated an issue. There are two broad lines of interpretation of Locke's moral views, which I will briefly outline here.

1.2 Critical interpretations of Locke's moral philosophy

The first interpretation of Locke's moral theory is what we might call an incompatibility thesis: Locke scholars Laslett, Aaron, von Leyden, among others, hold that Locke's natural law theory is nothing more than a relic from Locke's early years, when he wrote the Essays on the Law of Nature, and represents a rogue element in the mature empiricistic framework of the Essay. For these commentators, the two elements found in the Essay seem not only incommensurable, but the hedonism seems the obvious and straightforward fit with Locke's generally empiricistic epistemology. The general view is that Locke's rationalism seems, for all intents and purposes, to have no significant role to play, either in the acquisition of moral knowledge or in the recognition of the obligatory force of moral rules. These fundamental aspects of morality seem to be taken care of by Locke's hedonism. Worse than this, however, is that the two views rely on radically different epistemological principles. The conclusion tends to be that Locke is holding on to moral rationalism in the face of serious incoherence. The incompatibility thesis is supported by the fact that Locke seems to emphasize the role of pleasure and pain in moral decision-making, however it has difficulty making sense of the presence of Locke's moral rationalism in the Essay and other of Locke's later works (not to mention the exalted role he gives to rationally-deduced moral law). Added to this, even in Locke's early work, he seems to hold both positions simultaneously. Aaron and von Leyden both throw up their hands. According to von Leyden, in the introduction to his 1954 edition of Locke's Essays on the Law of Nature,

the development of [Locke's] hedonism and certain other views held by him in later years made it indeed difficult for him to adhere whole-heartedly to his doctrine of natural law. (Locke 1954, 14)

In a similar vein, Aaron writes:

Two theories compete with each other in [Locke's] mind. Both are retained; yet their retention means that a consistent moral theory becomes difficult to find. (Aaron 1971, 257)

Yet, it is curious that Locke neither claimed to find these strands incompatible, nor ever abandoned his rationalistic natural law view. It seems unlikely that this view would be nothing more than a confusing hangover from earlier days. Taking seriously Locke's commitment to both is therefore a much more charitable approach, and one that takes seriously Locke's clear commitment to the benefits of rationally-apprehending our moral duties. An approach along these lines is one we might call a compatibility approach to the question of Locke's moral commitments. John Colman and Stephen Darwall are two Locke scholars who have argued that Locke's view is neither plagued with tensions nor incoherent. Their common view is that the two elements of Locke's theory are doing different work. Locke's hedonism, on this compatibility account, is intended as a theory of moral motivation, and serves to fill a motivational gap between knowing moral law and having reasons to obey moral law. Locke introduces hedonism in order to account for the practical force of the obligations arising from natural law. As Darwall writes,

what makes God's commands morally obligatory [i.e., God's authority] appears…to have nothing intrinsically to do with what makes them rationally compelling. (Darwall 1995, 37).

Thus, on this account, reason deduces natural law, but it is hedonistic considerations alone that offer agents the motivating reasons to act in accordance with its dictates.

This interpretation convincingly makes room for both elements in Locke's view. A central feature of this interpretation is its attention to the legalistic aspect of Locke's natural law theory. For Locke, the very notion of law presupposes an authority structure as the basis for its institution and its enforcement. The law carries obligatory weight by virtue of its reflecting the will of a rightful superior. That it also carries the threat of sanctions lends motivational force to the law.

A slight modification of the compatibility account, however, better captures the motivational aspect of Locke's rationalistic account: Locke does, at times suggest that rational agents are not only obligated, but motivated, by sheer recognition of the divine authority of moral law. It is helpful to think of morality as carrying both intrinsic and extrinsic obligatory force for Locke. On the one hand moral rules obligate by dint of their divine righteousness, and on the other hand by the threat of rewards and punishments. The suggestion that morality has an intrinsic motivational force appears in the Essays on the Law of Nature and is retained by Locke in some of his final published works. It is, however, a feature of his view that gets somewhat underappreciated in the secondary literature, and for understandable reasons—Locke tends to emphasize hedonistic motivations. Why this is will be discussed in section 4. At this point, however, it suffices to say that Locke's theory does not have the motivational gap that the compatibility thesis suggests—hedonism serves as a ‘back-up’ motivational tool in the absence of the right degree of rational intuition of one's moral duty.

2. Locke's natural law theory: the basis of moral obligation

In order to get a complete understanding of Locke's moral theory, it is useful to begin with a look at Locke's natural law view, articulated most fully in his Essays on the Law of Nature (written as series of lectures he delivered as Censor of Moral Philosophy at Christ Church, Oxford). Two predominant features of Locke's natural law theory are already well-developed in this work: the rationalism and the legalism. According to Locke, reason is the primary avenue by which humans come to understand moral rules, and it is via reason we can draw two distinct but related conclusions regarding the grounds for our moral obligations: we can appreciate the divine, and thereby righteous, nature of morality and we can perceive that morality is the expression of a law-making authority.

2.1 Morality as Natural Law

In the Essays on the Law of Nature, Locke writes that “all the requisites of a law are found in natural law” (Locke 1663–4, 82). But, what, for Locke, is required for something to be a law? Locke takes stock of what constitutes law in order to establish the legalistic framework for morality: First, law must be founded on the will of a superior. Second, it must perform the function of establishing rules of behavior. Third, it must be binding on humans, since there is a duty of compliance owed to the superior authority that institutes the laws (Locke 1663–4, 83). Natural law is rightly called law because it satisfies these conditions. For Locke, the concept of morality is best understood by reference to a law-like authority structure, for without this, he argues, moral rules would be indistinguishable from social conventions. In one his later essays, “Of Ethic in General”, Locke writes

[w]ithout showing a law that commands or forbids [people], moral goodness will be but an empty sound, and those actions which the schools here call virtues or vices may by the same authority be called by contrary names in another country; and if there be nothing more than their decisions and determinations in the case, they will be still nevertheless indifferent as to any man's practice, which will by such kind of determinations be under no obligation to observe them. (Locke 1687–88, 302)

For Locke, then, moral law is, by definition, an obligatory set of rules, because it is reflects the will of a superior authority.

Moral rules are obligatory because of the authority structure out of which they arise. But, this is not the only story Locke has to tell regarding the nature of our obligation to divine moral dictates. The set of moral rules that reason deduces are taken by Locke to be reflective of human nature. The rules that govern human conduct are specifically tailored to human nature, and our duty to God involves realizing our natures to the fullest degree. There is a noticeable degree of teleology in Locke's theory, which is worth pausing to consider in its content and its implications.

2.2 Morality and Teleology

In the Essays on the Law of Nature, Locke draws a connection between the natural law governing human action and the laws of nature that govern all other things in the natural world; just as all natural things seem nomologically determined, so human beings are likewise law-governed. Humans are not determined to the same degree as other physical and biological entities, but we are beholden to God to ensure that our lives follow a certain path. Natural law is, Locke writes, a “plan, rule, or … pattern” of life (Locke 1663–64, 81). Locke's early view has a teleological strain typical of the Aquinian (and thus Aristotelian) tradition. In fact, Locke does not shy away from this teleological angle, acknowledging this inheritance when he writes of Aristotle's that he

rightly concludes that the proper function of man is acting in conformity with reason, so much so that man must of necessity perform what reason prescribes. (Locke 1663–64, 83)

Locke considers moral duty to be tailored to human nature, a set of laws specific to humanity and governing our actions according to God's will. These laws are not only discoverable by reason, but in order to fulfill our function, humans are required to make use of reason to this very end. This view resurfaces in the Essay, where Locke writes the following:

it will become us, as rational Creatures, to imploy those Faculties we have about what they are most adapted to, and follow the direction of Nature, where it seems to point us out the way. (Essay, 4.12.11)

The way it points us, he goes on to explain, is in the direction of our “greatest interests, i.e., the Condition of our eternal Estate” (Essay, 4.12.11). The greater effort we each make in refining our rational faculty, the more clearly each of us will discern the proper path to eternal salvation.

This teleological element may seem somewhat out of step with Locke's unqualified empiricistic rejection of teleological metaphysics in the Essay. However, it is important to bear in mind that the teleological aspects of Locke's moral theory do seem to be serving a very specific purpose. Locke seems to be aiming to establish a natural-theological basis for natural law. Why would this be so crucial for Locke?

Locke is grounding human conduct within a general framework of laws originating in God's divine command. This is not just a nomologically-ordered universe, but one, as we have seen, that reflects the interests of “a powerful and wise creator…who has made and built this whole universe and us mortals” (Locke 1663–64, 103) Humans are obligated to obey God's laws since God is a superior to whom we owe “both our being and our work” (Locke 1663–64, 105) As such, we are obligated to show obedience to the “limits he prescribes” (Locke 1663–64, 105). The laws governing our nature are discovered by reason and their content is specifically suited to human nature. Thus, for Locke morality is clearly and necessarily anthropocentric, understood by reference to human nature. But moral rules are, above all, an expression of God's will. It is this latter aspect of morality that binds us to abide by the dictates of morality. Moral obligation is a matter, for Locke, of obedience to the rightful authority of God.

2.3 Morality as a deductive science

There are two baseline assumptions of Locke's moral thinking: morality is universal and it is something that can be understood clearly and unequivocally by human reason—when Locke imagines us rationally-discovering natural law, he envisions us applying a rigorous set of logical principles to a set of clear and well-defined ideas about human nature, God, and society. But, how exactly is this done?

For one thing, this process looks a great deal like mathematical reasoning. For Locke, moral rules are founded on a fundamental set of principles, much like mathematical axioms. The fundamental principles can be deduced rationally, and it is from these that we can further derive all of our moral duties. Morality is, therefore, demonstrable, a term indicating mathematical-style proofs wherein conclusions are derived from axiomatic foundations. The moral status of any action is then determined by comparing our behaviour against these demonstrated rules. But, we might ask, what kinds of ideas are moral ideas, and what sort of rationalist could Locke possibly be? Locke is a well-known empiricist; for Locke, the mind is a blank slate, the content of which is supplied exclusively from sensory or reflective experience. Locke famously espouses this empiricistic view in the Essay, but holds it quite clearly also in Essays on the Law of Nature. In fact, however, Locke's moral rationalism takes this empiricistic theory of ideas as its starting point. Moral ideas, for Locke, are fundamentally experiential in origin. They are not directly so, of course, since we do not perceive something like justice or honesty directly. Moral ideas are experiential, in the special Lockean sense that they are complex ideas—products of the mind's ability to form complex constructions from its simple directly-experiential contents. For Locke, the interplay of reason and sensation works as follows:

reason is … taken to mean the discursive faculty of the mind, which advances from things known to things unknown and argues from one thing to another in a definite and fixed order of propositions… The foundations, however, on which rests the whole of that knowledge which reason builds … are the objects of sense-experience; for the senses primarily supply the entire as well as the chief subject-matter of discourse and introduce it into the deep recesses of the mind. (Locke 1663–64, 101)

From perceptual simple ideas, we can generate complex moral propositions. This seems like a tall order, and Locke offers very little, in any of his works, by way of actually putting this moral reasoning process to work. However, that is not to say that Locke is silent in this regard. There are places in his writings where Locke takes us through some moral demonstrations.

In the Essays on the Law of Nature, for example, Locke claims that, based on sensory experience, we can assert the extra-mental existence of perceptible objects and all their perceptible qualities. All such qualities can be explained by reference to matter in motion. What is also clear to the senses, Locke argues, is that this world of moving objects exhibits a nomological regularity, or as Locke puts it, a “wonderful art and regularity” (Locke 1663–64, 103). Such regularity and beauty leads the contemplative mind to consider how such a world could have come about. Such contemplation would lead any rational being to the conclusion that the world cannot be the result of chance, and must therefore be the product of a creative will. Note that Locke is here trying to demonstrate for us just how sensation and reason work together. The mind moves from ideas of sensation to what Locke considers logical conclusions regarding the creative force behind the world we experience. But, our understanding of natural law is not founded solely in sensory experience. Through reflection, which is an introspective kind of perceptual experience for Locke, humans can gain ideas of our own nature and faculties that serve to complete our understanding both of God and of God's creative will. This reasoning goes as follows—the creative being, which sensation indicates must exist, cannot be less perfect than human will, nor can it be human, because our ideas of reflection tell us that humans are not, and cannot be, self-causing. Reason must conclude, then, that the world is created by a divine will—a superior power, which can bring us into existence, maintain us, or take us away, give us great joy or render us in great pain. Locke concludes as follows:

with sense-perception showing the way, reason can lead us to knowledge of a lawmaker or of some superior power to which we are necessarily subject. (Locke 1663–4, 104)

From this deduction regarding divine purpose and authority, humans can conclude that they are obligated to render “praise, honour, and glory” to God. Beyond this, the rational agent can deduce, through reflection upon her own constitution and faculties, that her natural impulses to protect and preserve her life, and to enter into society with others are faculties with which she has been uniquely equipped by God and by which she is considered specifically human. These must constitute the basis of the principles and duties governing her conduct—her “function appears to be that which nature has prepared … [her] to perform” (Locke 1663–64, 105). Thus, by a series of steps from perception to reasoning about that perceptual experience, we are, Locke concludes, able to define our moral duties and regulate our conduct accordingly.

In the Essay, Locke develops this idea of the rational deduction of natural law somewhat further, setting it in the context of a more mature and coherent theory of ideas than we find in the Essays on the Law of Nature. In the Essay, moral ideas assume a particular significance owing to their place in Locke's general taxonomy of ideas. For Locke, all the basic contents of the mind are simple ideas. These are formed by the mind into what Locke terms complex ideas, which are combinations of simple ideas made in the pattern of our perceptions of things in the extra mental world, or according to a pattern created by reason alone. Moral ideas fall into the second category of complex idea, falling under the technical heading complex ideas of modes. Modes are a specific kind of complex ideas, created by the mind from simple ideas of sensation or reflection, but referring to no extra-mental reality. They are not intended as natural kinds, but are products of the mind alone, referring to purely conceptual archetypes. They are best understood in contradistinction to ideas of substances, which are created by the mind but aim to mirror the real essences of extra-mental things—for example, the idea cat is intended to capture a kind of thing in the world that has a specific set of perceivable characteristics. Ideas of substances fail in mirroring reality, however, as they can never be complete representations of the world outside the mind. Modal ideas, on the other hand, are a special kind of idea for Locke, and actually hold out the promise for real knowledge. Modal ideas are ideas by which we fully grasp the real essence of things, because the mind, in some sense, is the originator of them (I will return to this in the next paragraph). The idea of a triangle is a modal idea, made by reason and knowable in its essence with complete accuracy. The idea of a triangle is a product of the mind, and does not refer to anything outside the mind—i.e., any external archetype. The kinds of ideas that fall into this category are the idea of God, mathematical concepts, and, most importantly for our present purposes, moral concepts. Locke writes,

I am bold to think, that Morality is capable of Demonstration, as well as Mathematicks: since the precise real Essence of the things moral Words stand for, may be perfectly known; and so the Congruity, or Incongruity of the Things themselves, be certainly discovered, in which consists perfect knowledge. (Essay, 3.11.16)

Moral rules, for Locke, are knowable with the same degree of certainty as “any Demonstration in Euclid” (Essay, 4.3.18).

This might seem to be a tall order when considering the controversy generated by beliefs about moral rules, yet Locke clearly believes that moral rules can, with the right mental effort, yield indisputable universal laws. Locke offers an example of how this might work, by analyzing the moral proposition Where there is no property, there is no injustice. In order to see the demonstrable certainty of this claim, we have to examine the composite ideas and how those agree or disagree with one another. The idea of property, first of all, is a right to something. The idea of injustice, considered next, is a violation of that right. Given these definitions, which Locke thinks are arrived at by careful attention to definition, it is a rational deduction that injustice cannot exist if there is no property to be violated. Injustice and property must, by definition agree. This is a clearly demonstrable rule, according to Locke, deduced from clear and adequately conceived ideas. The only other example Locke offers is the proposition No Government allows absolute Liberty. Government, according to Locke, is the establishment of society upon certain laws, requiring conformity. Absolute liberty is allowing anyone to do as they please. These are modal ideas, according to Locke, and thus known with complete adequacy. As such, it is possible for the rational individual to see clearly that the ideas of absolute liberty and government cannot agree. Of course, most people will argue that these rational deductions rely upon definitions that are debatable. This would not seem to be helped by the fact that, for Locke, modal ideas, like all complex ideas, are put together by the mind; while complex ideas of substance are constructed on the pattern of perceivable objects, modal ideas are, Locke explains, “put together at the pleasure of our Thoughts, without any real pattern they were taken from” (Essay, 4.4.12). This might seem to pose a problem for Locke's moral theory, according to which moral laws are just as necessary as mathematical principles. However, Locke is not worried about any relativistic implications. For Locke, any disagreement about definitions of concepts like property, justice or murder, result from insufficient reasoning about the simple ideas that comprise our moral ideas, as well as bias, prejudice and other irrational influences. For Locke, it is precisely because these ideas refer to nothing outside the mind that they can be universally-conceived and adequately understood. Just as the notion of triangularity is known perfectly because it does not depend upon the existence of triangles outside the mind, so justice is understood perfectly because it is not using some extramental archetype as its inspiration. He writes,

the Truth and Certainty of moral Discourses abstracts from the Lives of Men, and the Existence of those Vertues in the World whereof they treat. (Essay, 4.4.8)

Mathematical concepts are impervious to bias, prejudice or otherwise-idiosyncratic definitions and their relative properties are clear to anyone who understands them perfectly. While many would contend that moral ideas are simply too controversial to fit a proto-mathematical picture, Locke would respond that they seem controversial only because many of us have not taken the time to consider moral ideas in an objective and analytical light. If we were to do so, he argues, we could come to know moral rules with certainty.

Locke, in fact, adds something of a meta-moral dimension to this epistemological point by suggesting that as rational beings it is our “proper Imployment” to contemplate morality. In Book IV of the Essay, where Locke concludes that morality is, like mathematics, a human science (and, properly-speaking, knowledge), Locke draws a teleological lesson—since we are clearly fitted with the capacity for discerning our moral duty, then that is what we ought to do: “I think I may conclude, that Morality is the proper Science and Business of Mankind in general.” (Essay, 4.12.11) Humans must, he argues, employ reason in the pursuit of that which “they are most adapted to, and follow the direction of Nature, where it seems to point us out the way” (Essay, 4.12.11). The fact that many people do not or cannot devote contemplative hours to their moral duties is something Locke will consider in his account of moral motivation, however, the key point here is that humans have a teleological makeup that allows for rational certainty with regard to divine moral law.

Is having this degree of knowledge enough to motivate humans to act accordingly—that is, does the sheer recognition of one's duty have any sway in one's practical deliberations?

3. Moral motivation 1: reward and punishment

Locke's hedonism has a dual function in Locke's moral theory. It accounts both for how we acquire the ideas of moral good and evil that lie at the root of moral law and for the motivation to comply with moral rules. A prominent feature of Locke's moral legalism is his view that a law needs to carry the threat of sanctions for it to have normative force. Locke holds this view on the basis of his hedonistic theory of human motivation.

3.1 Locke's general theory of motivation

Locke develops his hedonistic account most extensively in the Essay. According to this account, pleasure and pain are the primary motivating factors for all human action and human thought. Feelings of pleasure and pain accompany all our ideas, for Locke, prompting us to act in response to our perceptual experiences, and to move, in thought, from one idea to another. If we had no accompanying feeling of delight or pain in the face certain stimuli we would be unmoved to create music, eat when hungry, or even shift our attention from one idea to any other—the perception of rain would raise in us no different response than a sunny day, the idea of one's children would inspire no related thoughts of home or family, nor any discernibly different response from the idea of children one does not know. Locke writes,

we should have no reason to preferr [sic] one Thought or Action, to another; Negligence, to Attention; or Motion, to Rest. And so we should neither stir our Bodies, nor employ our Minds; but let our thoughts (if I may so call it) run a drift, without any direction or design; and suffer the Ideas of our Minds, like unregarded shadows to make their appearances there, as it happen'd, without attending to them. (Essay, 2.7.3)

Pleasure and pain are the engines that make decisions, thoughts, and actions happen. This is not merely coincidence, or chance, for Locke, but yet another example of God's divine design. God has attached feelings of pleasure and pain to our ideas, so the natural faculties with which humans are endowed “might not remain wholly idle, and unemploy'd by us” (Essay, 2.7.3).

3.2 Locke's theory of moral motivation

Pleasure and pain form the basis of Locke's general theory of motivation, but they are also the bedrock upon which our moral ideas, and the motivation to moral goodness arise. Good and evil reduce, for Locke, to “nothing but Pleasure or Pain, or that which occasions or procures Pleasure and Pain to us” (Essay, 2.28.5). A flower is good, because its beauty raises feeling of affection or pleasure in us. Illness, on the other hand, is an evil since it raises feelings of aversion in those who have experienced illness in any of its many forms. A good is whatever produces pleasure in us, or diminishes evil, and an evil is whatever produces pain or diminishes pleasure. In this way, for Locke, the ideas of good and evil arise from natural emotive responses to our various ideas. Now, these are not moral goods and evils, but for Locke moral ideas are founded in the general ideas we have of natural pleasures and pains. Locke designates no special faculty by which we acquire the basic moral concepts of good and evil, since these are merely a modification of our ideas of natural good and evil; moral good and evil gain their special significance from considering ideas of pleasure and pain in specific contexts.

Our ideas of moral good and evil do not, therefore, differ qualitatively from natural good or evil. If this is the case, however, one might ask what makes smelling a rose different from helping those in need. For Locke, the answer lies in the different context for pleasures and pains that distinguishes the moral from the natural. While a natural good involves the physical pleasure that arises from the scent of a rose, moral good is a pleasure arising from one's conformity to moral dictates, and moral evil is pain arising from the failure to conform. The pleasure and pain are not qualitatively distinct, in these cases, but they take on a special significance as a result of the considerations that bring them about. Locke explains this in the Essay, making sure to emphasize the purely contextual distinction between moral and natural feelings:

Morally Good and Evil then, is only the Conformity or Disagreement of our voluntary Actions to some Law, whereby Good and Evil is drawn on us, from the Will and Power of the Law-maker; which Good and Evil, Pleasure or Pain, attending our observance or breach of the law, by the Decree of the Law-maker, is that we call Reward or Punishment. (Essay, 2.28.5)

Reward and punishment are a distinct species of pleasure and pain, specifying the outcomes attending the decrees of a rightful legislator. In this way, Locke's is a straightforwardly legalistic account of the concepts of moral good and evil. The practical force of moral laws arises when we compare our actions against these laws, determine the degree to which they do or do not conform to the law and consider the pleasure of pain we will privately experience . In fact, for Locke, the very idea that one being has rightful legislative power over another is predicated on the degree to which the former being can effectively impose sanctions on the latter:

It would be in vain for one intelligent Being, to set a Rule to the Actions of another, if he had not in his Power, to reward the compliance with, and punish deviation from his Rule, by some Good and Evil, that is not the natural product and consequence of the action itself. (Essay, 2.28.6)

God, according to Locke, is just such a rightful superior with the

Goodness and Wisdom to direct our Actions to that which is best: and he has the Power to enforce it by Rewards and Punishments, of infinite weight and duration, in another Life. (Essay, 2.28.8)

Locke is clearly committed to the idea that hedonistically-construed outcomes are a necessary condition of any system of law and of legislative authority itself. In this regard, Locke's views are consistent throughout his corpus. It is worth noting that Locke holds the same view in the early work, the Essays on the Law of Nature, as he does in the more mature works quoted above. In the Essays on the Law of Nature, EssayV, Locke asserts that both God and the soul's immortality “must necessarily be presupposed if natural law is to exist” (Locke 1663–64, 113). The inclusion of the immortality of the soul would seem to suggest the centrality of rewards and punishments in the afterlife. Locke continues by asserting that “law is to no purpose without punishment” (Locke 1663–64, 113). For Locke, then, an agent may well know the moral law, and that they are obligated to a superior authority, but the obligatory force—i.e., what gives the agent a reason for acting—is the structure of rewards and punishments built into the system.

The question that has plagued Locke scholarship has been how, if at all, the hedonistic elements of Locke's moral philosophy can be reconciled with his rationalistic account, which suggests that reason can discern morality's inherent righteousness and motivate accordingly. Some scholars have concluded that Locke effectively abandons the rationalism of his earlier writings by the time he is writing the Essay, and that any such elements found therein are mere holdovers of an earlier position. Von Leyden expresses this view when he writes,

the development of [Locke's] hedonism and certain other views held by him in later years make it indeed difficult for him to adhere whole-heartedly to his doctrine of natural law. (von Leyden, 1954, 14)

But does it? What I earlier called the compatibilist thesis is held most prominently by scholars John Colman and Stephen Darwall, according to whom Locke's hedonism does not supplant the rationalist account of natural law and moral obligation, but is, rather, intended to account for the motivational force of moral law. In this way, the two views work together for a complete moral picture. Darwall identifies the distinction between rationally-derived versus legalistically-construed moral obligation when he writes

what makes God's commands morally obligatory [i.e., God's authority] appears…to have nothing intrinsically to do with what makes them rationally compelling. (Darwall 1995, 37)

Colman makes a similar point:

Right is the central concept in Locke's natural law doctrine, but the law could have no purchase on human conduct unless doing that which is right were in some way productive of good. ‘Good’ is the central concept in his moral psychology. (Colman 1983, 49)

Both Darwall and Colman understand Locke as equating moral good and evil with rewards and punishments, such that good and evil are the operative notions that turn moral rules into moral imperatives for rational agents. Agents do not have reasons for acting until they are aware of the rewards and punishments that accompany natural law. On this interpretation, rational insight regarding the righteousness of morality cannot, on its own, motivate humans to act.

Divine sanctions are a constant feature of Locke's moral philosophy, as we've seen, and the compatibilist interpretation goes much further than the incompatibilist interpretation in capturing the nuances in Locke's moral philosophy. However, there are passages in Locke's work that suggest that moral rules carry an obligatory force that can motivate rational agents irrespective of rewards and punishments. When this further aspect of Locke's view is taken into account, we can see that, for Locke, rewards and punishments do not exhaust our reasons for obeying divine moral rules.

4. Moral motivation 2: the righteousness of morality

In the Essays on the Law of Nature, Locke argues that there are two different kinds of obedience to the law of a superior authority, and that these are founded upon two distinct kinds of obligation. The example is as follows:

Anyone would easily … perceive that there was one ground of his obedience when as a captive he was constrained to the service of a pirate, and that there was another ground when as a subject he was giving obedience to a ruler; he would judge in one way about disregarding allegiance to a king, in another about wittingly transgressing the orders of a pirate or robber. (Locke 1663–64, 118)

At this point, Locke might be understood to be distinguishing laws backed by a rightful authority and laws that are not, in which the point is simply that there is no obligation to the pirate, since his are not strictly laws at all on Locke's definition of the term. However, Locke continues this passage as follows:

in the latter case [subject to a pirate or robber], with the approval of conscience, he rightly had regard only for his well-being, but in the former [subject to a king], though conscience condemned him, he would violate the right of another. (Locke 1663–64, 118)

Locke identifies two distinct grounds of obedience. Recognizing that one's obligation to the king arises from his rightful authority provides a grounds for obedience that is absent in the case of obeying the pirate. My reasons for obeying the pirate are hedonistic, but my reasons for obeying the king involve my recognition of his rightful authority. Further on in the same Essay, Locke explains that

We should not obey a king just out of fear, because, being more powerful he can constrain (this in fact would be to establish firmly the authority of tyrants, robbers, and pirates), but for conscience' sake, because a king has command over us by right; that is to say, because the law of nature decrees that princes and a lawmaker, or a superior by whatever name you call him, should be obeyed. (Locke 1663–64, 120)

Thus, sanctions are not the sole motivating factor for Locke. The contrast Locke draws here is an important but commonly underappreciated one; that is, acting for ‘conscience' sake’ versus acting ‘out of fear’ as two quite distinct grounds for obedience.

The question that remains is how Locke's notion of acting ‘for conscience' sake’ can be made sense of within the context of Locke's general hedonistic account of motivation. It might sound as though we are working with the kind of purely rational motivating factor that Locke's hedonistic theory clearly rejects; for Locke all human action is motivated by considerations of pleasure and pain.

Recall that for Locke rewards and punishments are specific pleasures and pains. Acting for conscious’ sake will necessarily involve considerations of pleasure and pain, but of a kind quite distinct from sanctions. For Locke, there is a kind of pleasure that attends fulfilling one's moral duty that is quite distinct from considerations of reward and punishment. In an essay, written in 1692, entitled Ethica A (the first of two essays, the other entitled Ethica B), Locke appeals to a kind of pleasure that attends the fulfilment of one's moral duty:

Whoever spared a meal to save the life of a starving man, much more a friend…but had more and much more lasting pleasure in it than he that eat it. The other's pleasure died as he eat and ended with his meal. But to him that gave it him ‘tis a feast as often as he reflects on it’. (Locke 1692, 319)

The pleasure here is of a special kind. It is not the same as the pleasure we get from satisfying our hunger, nor is it the pleasure that comes with pleasing an authority or earning a reward. In fact, Locke explicitly distinguishes it from the pleasure expected in the afterlife. Fulfilling one's duty, for Locke, carries its own kind of pleasurable motive—it makes us happy. As Locke writes, further on in Ethica A, “Happiness…is annexed to our loving others and to doing our duty, to acts of love and charity” (Locke 1692, 319). Acting according to moral duty, then, is motivated by feelings of pleasure that attend such acts.

Why, then, does Locke so frequently emphasize the legalistic angle of morality, which depends so heavily on the motivational force of reward and punishment? In Locke's view, many people fail to acknowledge, or be motivated by, the pleasure inherent to the fulfilment of one's moral duty, and for these people (which, it turns out, is most of us), God has provided extra incentive—the rewards and punishments God attaches to our actions are a matter of God's jurisdiction, quite apart from the pleasures of acting dutifully, and in accordance with righteous moral dictates. As Locke explains, God

brings in a necessity of another life…and so enforces morality the stronger, laying a necessity on God's justice by his rewards and punishments, to make the good the gainers, the wicked losers. (Locke 1692, 319)

Sanctions, therefore, serve to enforce morality ‘the stronger’ but are quite clearly secondary to the intrinsic pleasures motivating dutiful action. So, conscience does not motivate in and of itself, nor does the rational apprehension of one's moral duty, but Locke identifies a species of pleasure distinct from divine sanctions that makes his notion of acting for conscious' sake perfectly consistent with his hedonism: to act for conscious' sake is to be motivated by, and take pleasure in, acting in accordance with one's moral duty.

4.1 Locke's ethics of belief

Locke's emphasis can be explained by turning our attention to a view of human nature that lies at the root of Locke's account. Locke tends to be fairly pessimistic about the degree to which most humans appreciate the inherent righteousness of morality. In fact, Locke maintains a fairly low opinion of the willingness of most people to actually take the time to appreciate the righteousness natural law. If, he writes,

we will not in Civility allow too much Sincerity to the Professions of most Men, but think their Actions to be Interpreters of their Thoughts, we shall find, that they have no such internal Veneration for these Rules, nor so full a Perswasion of their Certainty and obligation. (Essay, 1.3.7)

Humans are flawed in two respects, according to Locke: we can fail to acknowledge our obligations to natural law, and we can fail to comply even when these obligations are acknowledged.

Locke's views regarding reason and intellectual duty can be characterized as an ethics of belief, according to which our rational abilities place a responsibility on each of us to examine the beliefs we hold, and to be accountable for those things to which we assent. This is particularly the case with respect to moral rules, themselves, which are the ultimate guidelines for a good human life. As Locke sees it, our capacities as rational agents are insufficiently realized in many, if not most, cases. While the law of nature is knowable by reason for Locke, it is not innately known—Locke does not mean to suggest, as many theologians of his day believed, that it “lies open in our hearts” (Locke 1663–64, 89). This would, he grants, be a

an easy and very convenient way of knowing, and the human race would be very well off if men were so fully informed and so endowed by nature that from birth they were in no doubt as to what is fitting and what is less so. (Locke 1663–64, 90)

For Locke, however, this is just not the case. It is clear, to him, that most people do not understand their moral duty in any deep or robust way. To really know one's moral duty is to be a moral agent, for Locke—moral knowledge is something gained, by the individual, through rational discovery. Moral truths are attainable with the proper use of reason:

there is some sort of truth to the knowledge of which man can attain by himself and without help of another, if he makes proper use of the faculties he is endowed with by nature. (Locke 1693–94, 89)

For Locke, knowledge, properly-speaking, requires that the individual herself perceives the truth or falsity of any claim to which she grants or withholds assent. An individual agent must perform the intellectual analysis and demonstration herself in order to truly know her moral duty. As it turns out, however, the greatest number of people (particularly in Locke's day), are, he acknowledges

given up to Labour, and enslaved to the Necessity of their mean Condition; whose lives are worn out, only in the Provisions of Living. (Essay, 4.20.2)

For these people, the opportunity for gaining a clear perception of their moral duty is very narrow. Worse than this, there are people who have the means and the leisure, but “satisfy themselves with a lazy ignorance” (Essay, 4.20.6). These latter, Locke asserts, have a “low Opinion of their Souls” (Essay, 4.20.6). But, in neither case are people entirely off the hook, according to Locke, who argues that no matter how busy one is, there should always be time for thinking about our souls and matters of religion. If one fails to do this, then one is relying for one's salvation and self-realization upon the mere current of opinion or the untrustworthy word of others. Locke asks if this can provide

sufficient Evidence and Security to every Man, to venture his greatest Concernments on; nay, his everlasting Happiness, or Misery. (Essay, 4.20.3)

The failure to do so is a kind of moral failing for Locke, one that gains its normative force from the teleogical imperative attending our rational natures:

God has furnished Men with Faculties sufficient to direct them in the Way they should take, if they will but seriously employ them that Way, when their ordinary Vocations allow them the Leisure. (Essay, 4.20.3)

Again, Locke is not suggesting that we do this from considerations of rewards and punishments, but because it is the fulfillment of our divinely-created natures. Despite failures to comply, the normative force of morality is undeniable, for Locke, on these teleogical grounds. Though Locke seems to believe that our failings with regards to moral knowledge result from a failure to engage our minds in the right direction, he does however acknowledge that the discovery of moral truths is difficult and laborious. And this is where sanctions come into play.

4.2 The special role of sanctions

Sanctions are not necessary to natural law if we consider it strictly as a system of divine rules. However, sanctions are necessary when morality functions as law. Sanctions are mechanisms for enforcement, where inherent motivating factors are either absent or underappreciated. Consider, as an example, the moral duty to care for one's children. For most people, this carries inherent obligatory force arising from its being obviously good and necessary. Where a person fails to appreciate the inherent force of this duty, however, laws exist that require parents to provide the means of life and education for their children, and such laws stipulate compliance under threat of sanctions. To call the first instance a law seems unnecessary, but we can clearly see how the concept of a rule of law distinguishes the latter case. Sanctions provide motives when individuals fail to act on the responsibilities reason should on its own reveal and thereby compel. In the Essays on the Law of Nature, Locke writes,

Those who refuse to be led by reason and to own that in the matter of morals and right conduct they are subject to a superior authority may recognise that they are constrained by force and punishment to be submissive to that authority and feel the strength of him whose will they refust to follow. (Locke 1663–64, 117)

Sanctions thus ensure that people who ‘refuse to be led’ by reason abide by the dictates of natural law; in this way, sanctions ensure that divine moral rules function as a system of law.

When Locke speaks of moral law, he frequently alludes to sanctions. Morality can motivate without sanctions, but it cannot ensure general compliance in the way that a system of law can. God's imposition of sanctions is thus strictly instrumental. They are not intrinsic to a system of morality, but they are necessary when the obligatory force of moral rules is not adequately understood. The special role of sanctions as a means of shoring up moral compliance is articulated by Locke in several of his writings. In the 1680 essay Of God's Justice, he writes

though justice be also a perfection which we must necessarily ascribe to the supreme being, yet we cannot suppose the exercise of it should extend further than his goodness has need of it for the preservation of his creatures in the order and beauty of the state that he has placed each of them in. (Locke 1680, 278)

God metes out justice in the form of sanctions as a means of ensuring social order and peace; sanctions ensure social good:

[God's] justice is nothing but a branch of his goodness, which is fain by severity to restrain the irregular and destructive parts from doing harm; for to imagine God under a necessity of punishing for any other reason but this, is to make his justice a great imperfection. (Locke 1680, 278)

In one of his more mature works, The Reasonableness of Christianity, Locke makes the point several times, that moral law, with its attendant rewards and punishments, was articulated as a means of ensuring obedience. Humans appreciate the intrinsic righteousness of virtuous acts, which are generally granted the highest degree of approbation. However, virtuous behaviour is assured only when it is in an agent's interests to comply. It is clear to reason that we ought to act virtuously, but it is easy enough for many of us to eschew virtuous actions when they either present hardships or sacrifice of any kind or when they will not clearly benefit our own interests:

The generality could not refuse [virtue] their esteem and commendation; but still turned their backs on her, and forsook her, as a match not for their turn. That she is the perfection and excellency of our nature; that she is herself a reward, and will recommend our names to future ages, is not all that can now be said of her. (Locke 1736, 247)

In order to remedy this problem, Locke explains, God attached clear and explicit sanctions (made plain through revelation) to ensure that the virtuous course of action will always be the more attractive option:

[Virtue] has another relish and efficacy to persuade men, that if they live well here, they shall be happy hereafter. Open their eyes upon the endless, unspeakable joys of another life, and their hearts will find something solid and powerful to move them. The view of heaven and hell will cast a slight upon the short pleasures and pains of this present state, and give attractions and encouragements to virtue which reason and interest, and the care of ourselves, cannot but allow and prefer. Upon this foundation, and upon this only, morality stands firm, and may defy all competition. This makes it more than a name; a substantial good, worth all our aims and endeavours; and thus the gospel of Jesus Christ has delivered it to us. (Locke 1736, 247)

Bibliography

Primary Literature: Works by Locke

Some of the works by Locke listed below can be found in Mark Goldie (ed.), Political Essays, Cambridge: Cambridge University Press, 1997.

  • 1663–64, Essays on the Law of Nature, in Goldie (ed.) 1997, 79–133.
  • 1680, “Of God's Justice,” in Goldie (ed.) 1997, 277–278.
  • 1686–88, “Of Ethic in General,” in Goldie (ed.) 1997, 297–304.
  • 1690, Two Treatises of Government, edited by Peter Laslett, Cambridge: Cambridge University Press, 1988.
  • 1692, “Ethica A,” in Goldie (ed.) 1997, 318–319.
  • 1700, An Essay Concerning Human Understanding, in P.H. Nidditch (ed.), An Essay Concerning Human Understanding, based on the fourth edition, Oxford: Oxford University Press, 1975.
  • 1736, John Locke, The Reasonableness of Christianity, As deliver'd in the scriptures, London: printed for A. Bettesworth and C. Hitch, in Paternoster-Row.
  • 1742, Familiar Letters between Mr. Locke and Several of his Friends, London: printed for F. Noble, T. Wright and J. Duncan in St. Martin's Court.

Secondary Literature

  • Aaron, Richard I., 1971, John Locke, Oxford: Clarendon Press.
  • Chappell, Vere, 1994, The Cambridge Companion to Locke, Cambridge: Cambridge University Press.
  • Cockburn, Catharine Trotter, 1702, “A Defense of Mr. Locke's Essay of Human Understanding,” in Catharine Trotter Cockburn: Philosophical Writings, P. Sheridan (ed.), Peterborough, ON: Broadview Press, 2006.
  • Colman, John, 1983, John Locke's Moral Philosophy, Edinburgh: Edinburgh University Press.
  • Darwall, Stephen, 1995, The British Moralists and the Internal Ought: 1640–1740, Cambridge: Cambridge University Press.
  • Dunn, John, 1969, The Political Thought of John Locke, Cambridge: Cambridge University Press.
  • Jolley, Nicholas, 2002, Locke: His Philosophical Thought, Oxford: Oxford University Press.
  • LoLordo, Antonia, 2012, Locke's Moral Man, Oxford: Oxford University Press.
  • Rossiter, Elliot, 2016, “Hedonism and Natural Law in Locke's Moral Philosophy,” in Journal of the History of Philosophy, 54(2): 203–255.
  • Schneewind, J.B., 1994, “Locke's Moral Philosophy,” in Chappell (1994).
  • Sheridan, Patricia, 2007, “Pirates, Kings, and Reasons to Act: Moral Motivation and the Role of Sanctions in Locke's Moral Theory” in Canadian Journal of Philosophy, 37(1): 35–48.
  • –––, 2010, Locke: A Guide for the Perplexed, London: Continuum Publishing Group.
  • –––, 2015, “Locke's Latitudinarian Sympathies: an exploration of sentiment in Locke's moral theory” in Locke Studies, 15: 131–162.
  • von Leyden, W., 1954, “Introduction,” in John Locke, Essays on the Law of Nature, W. von Leyden (ed.), Oxford: Clarendon.

1. Brief overview of Kant’s ethics

Although Kant’s ethics are discussed in relation to Hume’s ethics for much of this piece, we begin with five important features of Kant’s mature moral philosophy.

First, Kant places special importance on the a priori or “pure” part of moral philosophy. In Kant’s normative ethics in Metaphysics of Morals and lectures on ethics, Kant draws heavily on observations and ideas about human nature. But both in his normative works and in his foundational work, the Groundwork of the Metaphysics of Morals, Kant makes explicit that the supreme moral principle itself must be discovered a priori, through a method of pure moral philosophy (G 4:387–92). By “pure” or “a priori” moral philosophy, Kant has in mind a philosophy grounded exclusively on principles that are inherent in and revealed through the operations of reason. This sort of moral philosophy contrasts with empirical moral philosophy, which is grounded in a posteriori principles, principles inferred through observation or experience. While empirical moral philosophy, which Kant calls moral anthropology, can tell us how people do act, it cannot, Kant claims, tell us how we ought to act. And what we want to find, when we are seeking the supreme moral principle, is not a descriptive principle, but the most fundamental, authoritative normative principle. According to Kant, morality’s commands are unconditional. We could never discover a principle that commands all rational beings with such absolute authority through a method of empirical moral philosophy; we must use the a priori method. Moreover, we must keep the pure and empirical parts of moral philosophy clearly distinguished, since if we do not we could find ourselves confusing conditional truths, such as what is prudentially good for certain individuals or species, with unconditional truths about fundamental moral requirements (G 4:389–90). Once one has in hand the supreme principle of morality, however, one requires an understanding of human beings in order to apply it to them (MM 6:217). One can say little about what the supreme moral principle requires as duties human agents have to themselves and to one another without knowing such things as the sorts of ends people may be inclined to adopt and the conditions under which human agency will characteristically thrive or wither.

Second, Kant’s notion of autonomy is one of the more central, distinctive, and influential aspects of his ethics. Kant defines autonomy principally as “the property of the will by which it is a law to itself (independently of any property of the objects of volition)” (G 4:440). According to Kant, the will of a moral agent is autonomous in that it both gives itself the moral law (it is self-legislating) and can constrain or motivate itself to follow the law (it is self-constraining or self-motivating). The source of the moral law is not in the agent’s feelings, natural impulses or inclinations, but in her pure, rational will or noumenal self, which Kant identifies as the “proper self” (G 4:461). Heteronomous wills, on the other hand, are governed by some external force or authority—that is, by something other than a self-given law of reason. Kant assumes that all nonhuman animals, for example, are heteronomous, their wills governed by nature through their instincts, impulses, and empirical desires (G 4:444; CPrR 5:61).

It will be important in appreciating Kant’s response to Hume to note that, at least in his mature philosophy, Kant regards all moral theories prior to his as failing to explain the categorical nature of moral obligation and to articulate a supreme moral principle that could capture the categorical nature of morality, because those previous moral theories had neither recognized moral agents as autonomous in Kant’s sense, nor recognized that the supreme moral principle must be self-legislated (see Korsgaard 1996b; Wood 2005b; Schneewind 2009). According to Kant, only autonomous legislation can yield a categorical imperative; whereas heteronomous legislation can yield only hypothetical imperatives. Kant criticized for their assumption of heteronomy all theories that located the ground of moral obligation or of proper moral motivation in such things as self-love, sympathy, and fear of divine punishment or hope for divine reward (G 4:441–44; CPrR 5:39–41). It is also worth noticing that in addition to Kant’s describing all moral agents as autonomous (in that they are self-legislating and have the capacity to act rightly through their own self-constraint), Kant sometimes describes as autonomous ways of acting that realize the latter capacity—and as heteronomous ways of acting that fail to do so (G 4:440–41, 444; CPrR 5:29, 43, 78). Agents who are autonomous in the sense of being self-legislating do not consistently act rightly due simply to their commitment to morality; it is that latter way of acting that we might think of as the fullest expression of autonomy in action (cf. Baxley 2010, 57–61).

Third, Kant conceives of the human agent as having both noumenal and phenomenal aspects—or, as Kant sometimes puts it, being members of both the intelligible world and the sensible world. This point relates to the centrality of autonomy in Kant’s ethics, for it is in our membership in the intelligible world that Kant locates our freedom (G 4:451–52, 454; CPrR 5:43). Kant takes us to be both free and determined: free insofar as we are members of the noumenal world, determined insofar as we are members of the world of sense. The sensible world is in time, governed by laws of nature and open to empirical investigation; we are capable of attaining cognition of objects in this world. The noumenal world is neither in time nor governed by the laws of nature, but rather (somehow) grounds the laws that govern the world of sense, and underlies the world of appearance in other ways as well; objects in the noumenal world are not available for our cognition, but may be postulated (A 532–67, 633–35/B 560–95, 661–63; CPrR 5:132–48).

Fourth, Kant believes that morality presents itself to human agents as a categorical imperative, and that it is from this imperative, together with various facts about the world and our embodied agency, that we derive all specific moral duties. Kant says that the supreme moral principle is, for rational beings who do not necessarily follow the moral law, a categorical imperative (CI). It is an imperative because it commands and constrains us; it is a categorical imperative because it commands and constrains us absolutely, with ultimate authority and without regard to our preferences or empirical features or circumstances. A hypothetical imperative, by contrast, expresses a command of reason, but only in relation to an end already set by the agent, e.g., based on her inclinations (G 4:413–20). Perhaps the two best known formulations of the CI are the formula of universal law (FUL), which commands, “act only in accordance with that maxim through which you can at the same time will that it become a universal law” (G 4:421), and the formula of the end in itself (FEI), which commands, “So act that you use humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means” (G 4:429). These are the versions of the CI that Kant not only discusses, but also illustrates, in the second section of the Groundwork. Although he illustrates FUL and FEI in relation to maxims that he assumes to be obligatory or forbidden in the Groundwork, however, it is not until the Metaphysics of Morals that Kant argues systematically for duties by means of the CI and related principles, the universal principle of right (justice) and the supreme principle of virtue. The Metaphysics of Morals contains a “Doctrine of Right,” in which he explicates our innate right to freedom and discusses matters of private right (e.g., property and marriage) and public right (e.g., the right of the sovereign to punish subjects), and a “Doctrine of Virtue,” in which he explicates his notion of virtue, and argues for duties of virtue (such as the duties of avoiding servility and arrogance, and of promoting the ends of one’s own perfection and the happiness of others). Kant does not claim to derive these duties from the CI or the supreme principles of right or virtue alone. Rather, he draws on considerations regarding human nature and other aspects of the natural world in moving from general principles of morality to moral duties.

Fifth, Kant believes that morality gives rise to a notion of the highest good. Although the end that Kant’s ethics most closely concerns is rational nature (the “end in itself” which grounds moral duties), Kant’s ethics also contains a different sort of ultimate end: the complete object of practical reason, which we can think of all moral action as pointing toward. The highest good consists in a world of universal, maximal virtue, grounding universal, maximal happiness (CPrR 5:110–11). One reason that Kant’s account of the highest good is important is that it emphasizes that, for Kant, virtue is unconditionally good, whereas happiness is conditionally good; happiness is good when and only when it is pursued and enjoyed virtuously. These two components of the highest good are heterogeneous. No amount of happiness can make up for a deficit of virtue, and no amount of virtue—despite its unconditioned goodness—can make up for a deficit of happiness. The highest good requires both. Another reason that Kant’s account of the highest good is important is that Kant often portrays the highest good as a social good for us to strive for collectively, and which we may view history as leading toward; this shows Kant’s ethics to be less abstract and individualistic and more concerned with social and political progress than some of his more foundational writings suggest it is. A final reason that Kant’s account of the highest good is important is that it is through his account of the highest good that Kant argues for the rationality of belief in God and immortality. For example in the Critique of Practical Reason, Kant argues that because reason sets forth the idea of happiness conditioned by and proportionate to virtue as the ultimate culmination of our moral strivings, we must believe this end to be realizable; for if we do not believe it can be realized, we must admit that morality directs us to an empty ideal, and hence is itself fraudulent. But since this end does not seem attainable entirely through human agency in the natural world, we must, if we are to believe it is possible, postulate the existence of God, who mediates between the realms of nature and freedom, allowing morally good intentions to be expressed through actions in the natural world, and virtue to ground proportional happiness (CPrR 5:124–26). This argument does not give us knowledge of God’s existence, but rather practical warrant for belief in God. Moreover, it depends on the impossibility of proving that God does not exist; for this practical warrant would not hold in the face of theoretical proof of God’s nonexistence. But Kant believes that speculative arguments can prove neither God’s existence nor God’s nonexistence. Thus, Kant’s account of the highest good shows how, for Kant, moral commitment leads to religious belief. (Kant also argues that we must postulate the immortality of the soul, since otherwise it seems impossible for us to bring our dispositions into complete compliance with the moral law (CPrR 5:122–24).)

2. Brief overview of Hume’s ethics

Five important aspects of Hume’s moral theory are the following.

First, Hume’s approach to ethics could be called naturalistic, empirical, or experimental. There are a variety of reasons for this. Hume’s ethics is part of his larger philosophical endeavor to explain naturalistically all aspects of human nature—not just what we can know of the world around us, but also how we make moral judgments and why we have religious beliefs. Hume’s ethics relies on and reflects his philosophy of mind, which is empirical in its approach. He intends to use the same experimental method in analyzing human morality that he uses in analyzing human understanding. Hume treats ethics, together with psychology, history, aesthetics, and politics, as the subject of his “moral science.” Hume often seems more interested in explaining morality as an existing natural phenomenon than in setting out a normative ethical theory. Hume seeks to displace a priori conceptions of human nature and morality with an approach according to which everything about us is open to empirical investigation and to explanation in naturalistic terms. Hume often compares humans with other animals, tracing the bases of human morality to features we share with them. Hume talks about morality and virtue as independent of religion and the supernatural, and about moral action as part of the same physical world in which we reasonably talk of in terms of cause and effect (EHU 8.1.20–22).

Second, according to Hume, moral judgments are essentially the deliverances of sentiment (EPM App.1.3). We recognize moral good and evil by means of certain feelings: the calm pleasure of moral approval or the discomfiting displeasure of moral disapproval, either of which may be felt in contemplating a character trait in oneself or another from an unbiased perspective (“the general point of view”). According to Hume, traits—be they feelings, motives, or abilities—that elicit our approval are those that are useful or agreeable to oneself or others; those that elicit our disapproval are those that are harmful or unpleasant for oneself or others. We call the traits that elicit our approval “virtues,” and those that elicit our disapproval “vices.” Hume assumes that we all have the same moral feelings, that is, that if we all take up the moral point of view, we will all agree in our approvals and disapprovals of various traits. The operation of our sentiments of moral approval and disapproval depend on sympathy, which allows the feelings of one person to be shared by others. Although Hume believes that only human beings experience moral sentiments, he believes that nonhuman animals also have sympathy, and thus share with us one of the essential foundations of morality.

Third, Hume’s ethics contains an extensive and diverse set of virtues. In Hume’s ethics, character traits are the primary object of moral assessment. Acts are judged derivatively, in relation to the traits assumed to cause them. In the Treatise, he divides virtues into the categories of natural virtues (e.g., beneficence and temperance) and artificial virtues (e.g., justice and fidelity to promises). Natural virtues are those traits that are useful or agreeable to people whether or not they are living in a large society, whereas artificial virtues are those traits that emerge as useful or agreeable in social groups that go beyond families or small communities, and in which social cooperation is needed among people with few or no personal ties. Natural virtues produce benefit or enjoyment with far greater reliability than artificial virtues do. Indeed, only natural virtues are characteristically pleasing on all occasions of their expression. Artificial virtues benefit people not consistently on each occasion, but rather through their wide-spread practice over time throughout a community (T 3.3.1.12).

Fourth, Hume provides only a limited (though not unimportant) role to reason in ethics. The principal role that Hume gives to reason in ethics is one of helping agents see which actions and qualities are genuinely beneficial or efficacious. Hume denies that reason itself sets the standard of morality, or sets forth certain ends as morally to be promoted. Reason, according to Hume, is a faculty concerned with truth or falsehood, both demonstrably in the realm of relations of ideas and empirically in the realm of matters of fact. Reason makes inferences, but neither sets ends, nor motivates action. Our ends depend on what we desire, which depends on what we feel (with respect to pleasure and pain). “Reason, being cool and disengaged, is no motive to action, and directs only the impulse received from appetite or inclination, by showing us the means of attaining happiness or avoiding misery: Taste, as it gives pleasure or pain, and thereby constitutes happiness or misery, becomes a motive to action, and is the first spring or impulse to the desire and volition” (EPM App.1.21). Once feeling has established utility as one of the primary objects of morality, reason is essential to determine which character traits or modes and conduct conduce to it. This task is especially difficult with regard to questions of artificial virtues, such as justice, since so many people are involved, and since the social benefits of these virtues can be expected only from (possibly tong-term) collective action (EPM App.1.2). Reason has other roles related to morality, too. For example, Hume notes that in order to make a moral judgment, one must have in mind all the relevant facts, and apprehend all the relevant relations of ideas. This takes reason. The moral judgment itself, however, is not possible without sentiment, which takes in all the deliverances of reason and emerges with something beyond them: the sentiment of approval or disapproval.

Fifth, Hume takes morality to be independent of religion. In his ethical works, he clearly tries to ground morality in human nature, and to make a case for morality that stands just as well without a theistic underpinning as with one. He argues not so much against belief in God as for the irrelevance of God to morality. Moreover, by basing morality in sentiment, he excludes God as a moral assessor. In Dialogues Concerning Natural Religion he considers and refutes the main speculative arguments for the existence of God. In his A Natural History of Religion, he provides an account of how religion emerged from human nature within the human predicament.

3. Hume’s influence

Before considering Kant’s response to Hume, we should note a few things about Hume’s influence on German philosophy, and Kant’s access to and direct impression of Hume’s work in ethics.

First, works by prominent British philosophers received much attention in Germany and Prussia in Kant’s day (Kuehn 2001, 107–108, 183). Hutcheson and Hume, for example, were much discussed in the philosophical communities not only in Berlin, but also in Königsberg, where Kant spent his life. The works of these philosophers were translated from English to German, and often reviewed in scholarly journals. Hume’s Enquiry concerning Human Understanding appeared in German in 1755.

Second, it is hard to know exactly which works of Hume and other British moral philosophers Kant read. Kant owned the 1762 German editions of Hutcheson’s An Inquiry into the Original of Our Ideas of Beauty and Virtue (1725) and An Essay on the Nature and Conduct of the Passions, with Illustrations of the Moral Sense (1728) (Schneewind 1998, 501). He seems to have read Adam Smith’s Theory of Moral Sentiments in the 1770 German translation (Schneewind 1998, 378). Kant might have had access to a German edition of Hume’s Treatise of Human Nature, since his friend Hamann owned one (Kuehn 2001, 265, 482). Otherwise, we must suppose that his knowledge of it came second hand, from reviews, other writings, and discussion with people who had read such works.

Third, whether direct or indirect, the influence of Hume and other moral sense theorists on Kant was profound—according to Kant himself. In Kant’s lectures and elsewhere, he makes explicit his view that Shaftesbury, Hutcheson, and Hume were making significant contributions to ethics (Schneewind 1998, 378). It is worth noting, however, that Kant often indicated that he saw Hutcheson as more significant to ethics than Hume. Kant seems to have associated Hutcheson more with the positive insights about the role of sensibility in ethics, whereas he seems to have associated Hume more with skepticism about practical reason (Kuehn 2001, 182).

4. Sentimentalism’s influence and the problem of obligation

The influence of British sentimentalist ethics on Kant seems to have been strongest during the early to middle 1760s. Perhaps the piece of writing that most clearly exhibits both the influence of sentimentalism on Kant and his distinctive take on it is Observations on the Feeling of the Beautiful and the Sublime (1764). His project in this work involves noting and analyzing the various feelings of pleasure or displeasure, and attraction and aversion, people feel to different traits and temperaments in themselves and others (and to different types of literature, objects in nature, kinds of relationships, and other things). In addition to apparent similarities in endeavor and language (e.g., of “moral beauty”) between Kant’s project here and the work of sentimentalists, Kant makes some statements about the foundation of morality and its principles that are striking in their sentimentalist cast. For example, consider these two passages, which both reflect the influence of sentimentalism and foreshadow Kant’s later work in ethics:

[I]f, by contrast, general affection towards humankind has become your principle, to which you always subject your actions, then your love towards the one in need remains, but it is now, from a higher standpoint, placed in its proper relationship to your duty as a whole. The universal affection is a ground for participating in his ill-fortune, but at the same time it is also a ground of justice, in accordance with whose precept you must now forbear this action [of helping him with money you owe to another]. Now as soon as this feeling is raised to its proper universality, it is sublime, but also colder. (OFBS 2:216)
[T]rue virtue can only be grafted upon principles, and it will become the more sublime and noble the more general they are. These principles are not speculative rules, but the consciousness of a feeling that lives in every human breast and that extends much further than to the special grounds of sympathy and complaisance. I believe I can bring all this together if I say that it is the feeling of the beauty and the dignity of human nature. The first is a ground of universal affection, the second of universal respect, and if this feeling had the greatest perfection in any human heart then this human being would certainly love and value even himself, but only in so far as he is one among all to whom his widespread and noble feeling extends itself. Only when one subordinates one’s own particular inclination to such an enlarged one can our kindly drives be proportionately applied and bring about the noble attitude that is the beauty of virtue. (OFSB 2.217)

Other indications of the sentimentalist influence on Kant can be found in his notes and lectures from that period. For example, the announcement of his lectures for the winter semester of 1765–1766, in which Kant states his intention to develop and clarify “the attempts of Shaftesbury, Hutcheson and Hume, which, though imperfect and defective, have nevertheless come farthest in the discovery of the first principles of all morality” (Ak 2:311, translated by and quoted in Kuehn 2001, 176). Also, in notes that appear to come from between 1764 and 1768, Kant writes, “[t]he rules of morality proceed from a special, eponymous feeling, upon which the understanding is guided …” (NF 19:93 #6581).

If Kant was genuinely trying out a version of sentimentalism in the early 1760s, this phase did not last long, nor was it a simple adoption of the theories of Shaftesbury, Hutcheson, or Hume. Kant’s description of the sentimentalist approach to ethics as “imperfect and defective” indicates a brief or incomplete acceptance of their approach to ethics. Moreover, in Observations, his account of true virtue and moral principles anticipates later discussions of these topics in which he will reject sentimentalism. For example, in Observations, Kant frequently and explicitly distinguishes between “true virtue” and all the “adoptive virtues” or “assisting drives,” locating sympathy and benevolence in the second group. In Kant’s more mature writing, he maintains the division between true virtue (which alone is sublime) and these same assisting drives (which can only be beautiful). But in his later works, Kant explicitly identifies true virtue with a rationally grounded commitment to morality, not with an initially pathological feeling of affection which has been universalized and cooled.

Interestingly, however, Kant makes comments about the importance of these assisting drives in his later works that echo those in Observations, even when they seem (at least on the surface) to sit ill with some of his other mature claims about the practicality of pure reason. Compare, for example, what Kant says in Observations with what he says in the Metaphysics of Morals (1797):

In recognition of the weakness of human nature and the little power that the universal moral feeling exercises over most hearts, providence has placed such helpful drives in us as supplements for virtue, which move some to beautiful actions even without principles while at the same time being able to give others, who are ruled by these principles, a greater impetus and a stronger impulse thereto. (OFBS 2:217).
But while it is not in itself a duty to share the sufferings (as well as the joys) of others, it is a duty to sympathize actively in their fate; and to this end it is therefore an indirect duty to cultivate the compassionate natural (aesthetic) feelings in us, and to make use of them as so many means to sympathy based on moral principles and the feeling appropriate to them… . For this [compassion] is still one of the impulses that nature has implanted in us to do what the representation of duty alone might not accomplish. (MM 6:457)

Kant also continues to believe some version of his claim at the beginning of Observations that some of our feelings indicate a “susceptibility of the soul which … makes it fit for virtuous impulses” (OFBS 2:208). We see this in the Metaphysics of Morals discussion of moral feeling, conscience, love of one’s neighbor, and self-respect, which he says “lie at the basis of morality, as subjective conditions of receptiveness to the concept of duty,” which every human being has, and by virtue of which everyone can be put under moral obligation (MM 6:399) (see Guyer 2010).

Despite the appeal that sentimentalism clearly held for Kant in the 1760s, by the late 1760s it was a theme of Kant’s notes and lectures that moral sense theories could not provide adequate accounts of moral obligation. Arguments for this conclusion appear in Kant’s later written works and lectures. In a number of works, Kant creates taxonomies of misguided, heteronomous ethical theories based on material determining grounds—in contrast to his theory of autonomy, in which the moral motive constitutes an objective, formal determining ground. (See Wood 2005b; Irwin 2009, chapters 68 and 71; and Schneewind 2009.) Kant distinguishes among these theories based on their accounts of the basis of moral obligation or the fundamental moral principle (G 4:441–44; CPrR 5:39–41; C 27: 252–54; M 29:621–25). Such theories may assume either subjective (empirical) or objective (rational) determining grounds for the moral principle; and within each of these categories, there are theories that assume these determining grounds are external, and others that assume they are internal. Objective, internal grounds include perfection (e.g., Wolff and the Stoics). Objective, external grounds include the will of God (e.g., Crusius). Subjective, external grounds include education (e.g., Montaigne) or civil constitution (e.g., Mandeville). Subjective, internal grounds can include physical feeling, such as self-love (e.g., Epicurus) or self-interest (e.g., Hobbes), or moral feeling (e.g., Hutcheson) (CPrR 5:40; C 27:253). Thus, Kant locates moral sense theories among those theories that assume a subjective, empirical, internal determining ground of moral feeling as the principle of morality:

What, then, is the basis of morality? … From what power does the principle come, and how does it run? … Those who assume a moral sense, whereby we are supposedly able, by feeling, to perceive the propriety or impropriety of our actions, have the principle of moral feeling. Shaftesbury introduced it, and had many Englishmen, including Hutcheson, among his followers. The moral and the empirical senses are both internal empirical grounds. (M 29:621)

Kant displays some level of relative approval for the moral sense theories. He compares them favorably with theories of self-interest, for example. Although he states that the principle of moral sense theories falls under the principle of happiness because all empirical interests promise to contribute to our happiness, moral feeling “nevertheless remains closer to morality and its dignity in as much as it shows true virtue the honor of ascribing to her immediately the delight and esteem we have for her and does not, as it were, tell her to her face that it is not her beauty but only our advantage that attaches us to her” (G 4:442–43).

Ultimately, of course, sentimentalism, along with all other attempts to ground morality in material determining grounds, fails in Kant’s view. Kant has a lengthy list of related reasons why moral sense theories are inadequate. No empirical principles can ground moral laws, because moral laws bind all rational beings universally, necessarily, and unconditionally; empirical principles are contingent in various ways, for example, on aspects of human nature (G 4:442–43). Variance in moral feelings makes them an inadequate standard of good and evil (G 4:442). Moral feelings cannot be the source of the supreme moral principle, because the supreme moral principle holds for all rational beings, whereas feelings differ from person to person (M 29:625). If duty were grounded in feeling, it would seem that morality would bind some people (e.g., the tender-hearted) more strongly than others, contrary to the universal, equal nature of moral obligation. Even if people were in complete agreement regarding their moral feelings, the universality of these feelings would be a contingent matter, and thus an inadequate ground for the unconditionally binding moral law. Indeed, if morality were grounded in feeling, it would be arbitrary: God could have constituted us so that we would get from vice the pleasurable, calm feelings of approval that we now (allegedly) get from virtue (M 29:625). So for Kant, the contingency of the ground of obligation offered by moral sense theories renders those theories inadequate; only a priori determining grounds will do.

Nevertheless, we can see the extent of the influence of moral sense theories on Kant’s ethics in the way that moral feeling continued to figure in Kant’s moral thought long after he rejected moral sense theories as heteronomous. Kant states in his notes that moral sense theories are better understood as providing a hypothesis explaining why we in fact feel approval and disapproval of various actions than as supplying a principle that justifies approval or disapproval or that guides actions (NF 19:117 # 6626). Kant suggests that even if one rejects moral sense “as a principle for the judgment of moral action” one might still accept it as a theory “of the mind’s incentives to morality” (M 29:625). Similarly, Kant declares, “Moral feeling does not pertain to the giving of laws, but is the basis of their execution” (M 29:626). As noted, Kant’s later works give an important role to certain moral feelings—moral feeling, conscience, self-respect, and love of one’s neighbor—as constituting subjective conditions for moral obligation. Although Kant takes many pathological feelings (such as sympathy and parental love) to be of vast moral usefulness, and worthy of cultivation for moral purposes, Kant puts conscience, moral feeling, self-respect, and love of one’s neighbor in a special category of feelings. He puts them in the category of “natural predispositions of the mind … for being affected by concepts of duty” and says that “[c]onsciousness of them is not of empirical origin; it can, instead, only follow from consciousness of a moral law, as the effect this has on the mind” (MM 6:399). As early perhaps as 1772, Kant can be seen to be giving moral feeling a special status in relation to reason. Kant writes that “[m]oral feeling succeeds the moral concept, but does not produce it; all the less can it replace it, rather it presupposes it” (NF 19:150 #6757). Perhaps even earlier, he writes that “[t]he moral feeling is not an original feeling. It rests on a necessary inner law …” (NF 19:103 #6598).

Kant develops his notion of moral feeling as a feeling that follows from rather than proceeds, or is independent of, consciousness of the moral law most fully in “On the Incentives of Pure Practical Reason” in the second Critique. Here Kant sets out an account of moral feeling as identical with the feeling of respect for the law, describing it as “a feeling that is produced by an intellectual ground, and … the only one that we can cognize completely a priori and the necessity of which we can have insight into” (CPrR 5:73). Kant explains, “there is no antecedent feeling the in subject that would be attuned to morality: that is impossible, since all feeling is sensible whereas the incentive of the moral disposition must be free from any sensible condition. Instead, sensible feeling … is indeed, the condition of that feeling we call respect, but the cause determining it lies in pure practical reason” (CPrR 5:75). “This feeling … is therefore produced solely by reason. It does not serve for appraising actions and certainly not for grounding the objective moral law itself, but only as an incentive to make this law its maxim” (CPrR 5:76). Kant’s treatment of moral feeling is surely one of the more significant ways in which he integrates what he sees as the valuable insights of moral sense theorists into his own theory.

5. Freedom of the will

Hume sets out his views concerning freedom of the will in Book II, Part 3, of A Treatise of Human Nature, and in section VIII of An Enquiry Concerning Human Understanding, “Of Liberty and Necessity.” The position that emerges from these works is compatibilist, in that Hume argues both that all human actions are caused (and caused with the same necessity as all other events) and that we have liberty of action. As attention to Hume’s arguments in the Enquiry will reveal, however, the kind of liberty that Hume ascribes to human beings is more superficial—more an account of freedom of action—than what is often desired by those arguing for freedom of the will. Indeed, for Hume, the very notion of will is problematic. In the Treatise, he calls it “impossible to define,” and provides the following deflationary account of it: “by the will, I mean nothing but the internal impression we feel and are conscious of, when we knowingly give rise to any new motion of our body, or a new perception of our mind” (T 2.3.1.2). Another point worth recognizing at the outset about Hume’s arguments in the Enquiry is that the kind of necessity he ascribes to human actions is the distinctively Humean one, according to which necessity “consists in the constant conjunction of like objects, or in the inference of the understanding from one object to another,” which he takes to be “at bottom, the same” (EHU 8.2.27).

Hume begins his discussion in the Enquiry by suggesting that ambiguities in language have kept interlocutors in the debate over freedom of the will talking past one another. Indeed, according to Hume, “all mankind, both learned and ignorant, have always been of the same opinion with regard to this subject, and … a few intelligible definitions would immediately have put an end to the whole controversy” (EHU 8.1.2). Hume sets out to clarify what we can best be understood to mean when we talk about liberty and necessity, and to show that so understood, there is no conflict between them.

He discusses necessity first. He argues thus: “It is universally allowed that matter, in all its operations, is actuated by a necessary force, and that every natural effect is so precisely determined by the energy of its cause, that no other effect, in such particular circumstances, could possibly have resulted from it” (EHU 8.1.4). “Our idea … of necessity and causation arises entirely from the uniformity, observable in the operations of nature; where similar objects are constantly conjoined together, and the mind is determined by custom to infer the one from the appearance of the other” (EHU 8.1.5). “It is universally acknowledged, that there is a great uniformity among the actions of men, in all nations and ages, and that human nature remains still the same, in its principles and operations” (EHU 8.1.7). It is on the basis of the observed uniformity among human actions that we draw inferences concerning them, just as it is on the basis of observed uniformity among events in the natural world that we draw inferences concerning them (EHU 8.1.16). When we think about how we interact with others and how we reflect on human actions through history and politics, it “seems almost impossible … to engage, either in science or in action of any kind, without acknowledging this doctrine of necessity, and this inference from motives to voluntary actions; from characters to conduct” (EHU 8.1.18). Finally, “when we consider how aptly natural and moral evidence link together, and form only one chain of argument, we shall make no scruple to allow, that they are of the same nature, and derived from the same principles” (EHU 8.1.19). Hume’s conclusion is that “the same necessity [is] common to all causes,” human and non-human (EHU 8.1.21).

Given his claim that if we reflect honestly and carefully, we can all recognize that we are committed to accepting this sort of necessity’s pertaining to human actions, Hume must explain why people have not generally believed that human actions are determined as natural events are. He locates the problem in part in a reluctance to accept his general account of necessity as a mere link the mind makes between one object or event and another based on experience of their correlation:

[M]en still entertain a strong propensity to believe, that they penetrate farther into the powers of nature, and perceive something like a necessary connection between the cause and the effect. When again they turn their reflections towards the operations of their own minds, and feel no such connexion of the motive and the action; they are thence apt to suppose, that there is a difference between the effects, which result from material force, and those which arise from thought and intelligence. (EHU 8.1.21)

When it comes to liberty of action in human beings, Hume declares, “We cannot surely mean, that actions have so little connexion with motives, inclinations, and circumstances, that one does not follow with a certain degree of uniformity from the other, and that one affords no inference by which we can conclude the existence of the other” (EHU 8.1.23). Any such view of liberty would fly in the face of both common and philosophical ways of thinking about human action. Instead, what we mean by liberty is simply, “a power of acting or not acting; according to the determinations of the will; that is, if we choose to remain at rest, we may; if we choose to move, we also may.” Every person “who is not a prisoner and in chains” has this liberty (EHU 8.1.23).

Hume argues that his notions of liberty and necessity are not only consistent with each other, but that both of them are consistent with, and even essential to, basic moral and legal practices (EHU 8.2.27–31). For example, we are far more condemnatory in blaming and punishing someone for an act we regard as caused by an enduring trait, motive, or inclination than one we regard as caused by a fleeting feeling, which is less deeply a part of that person. And it would make no sense at all to blame someone for an action the cause of which lay entirely outside her. Hume gives a mixed verdict to questions about whether his arguments about liberty and necessity pose problems for beliefs about God’s omnipotence and beneficence, arguing that while some standard arguments can handle one type of concern that might arise, not all such concerns can be dealt with so easily (EHU 8.2.32–36).

Kant shares Hume’s view that causal necessity governs human actions and other events, insofar as they are all considered part of the natural world, and that humans are nonetheless free. But Kant rejects Hume’s view that moral and natural actions must be viewed as part of a single chain of causes, effects, and explanations. Indeed, if they were, and if we accepted natural causal laws as universal and deterministic, there could be no freedom of the sort Kant is ultimately after for his moral philosophy (i.e., autonomy). Kant renders freedom and determinism consistent by distinguishing between two worlds of which we are members. As members of the phenomenal world, our actions can be understood in purely deterministic terms, according to natural causal laws; but as members of the noumenal world, we are free. (Lest the notion of “two worlds” seem spooky or wildly implausible, Kant states: “The concept of a world of understanding is … only a standpoint that reason sees itself constrained to take outside appearances in order to think of itself as practical” (G 4:458).) Thus, Kant endorses “not only the compatibility of freedom and determinism, but also the compatibility of compatibilism and incompatibilism” (Wood 1984, 74). Kant also rejects Hume’s account of necessity:

[T]he very concept of a cause so manifestly contains the concept of a necessary connection with an effect and of the strict universality of the rule, that the concept would be altogether lost if we attempted to derive it, as Hume has done, from a repeated association of that which happens with that which precedes, and from a custom of connecting representations, a custom originating in this repeated association, and constituting therefore a merely subjective necessity. (B 4–5)

For Kant, the judgment “every alteration must have a cause” is a pure, a priori judgment, and the concept of cause necessary for the very possibility of experience. (See also B 19–20, A 760–61/B788–89; Prol 4:260–61, 310–13.) (See Guyer 1987, esp. ch. 10.)

To provide a rough sense of Kant’s theory of freedom, we set out a few of Kant’s claims and arguments about freedom from the Critique of Pure Reason, the Groundwork of the Metaphysics of Morals, and the Critique of Practical Reason. But note that there are a couple of aspects of his view that are not discussed in those contexts. One is a distinction Kant makes (at least from the second Critique onward) between Wille and Willkür, two aspects or functions of the faculty of volition (MM 6:213–14, 226). Wille is the legislative aspect; it is through Wille that rational beings give our selves the law; and it is Wille that Kant identifies with pure practical reason. Wille is itself neither free nor unfree. Willkür is the executive aspect or function of the faculty of volition, and is the aspect of it that is properly regarded as free. An agent chooses morally when the subjective principles of her Willkür (i.e., her maxims) conform to the objective principles of her Wille. (In addition to Kant’s sometimes deviating from consistent use of these terms, matters are complicated by his using “Wille” as the general term for the faculty of volition.) A related aspect of Kant’s theory of freedom is what Henry Allison calls Kant’s “Incorporation Thesis,” according to which particular inclinations, impulses, and feelings do not constitute reasons for action unless an agent has a maxim of satisfying them (See Allison 1990, esp. 40–41, 189). Kant appears to state this view when he says, “freedom of the power of choice [i.e., Willkür] has a character entirely peculiar to it, that it cannot be determined to an action through any incentive except so far as the human being has incorporated it into his maxim (has made it into a universal rule for himself, according to which he wills to conduct himself)” (Rel 6:24). (For critical discussion of the Incorportation Thesis, see McCarty 2009, chapters 3 and 4.)

The most important arguments regarding freedom in Kant’s first Critique concern the Third Antinomy. In this work, Kant is primarily concerned with transcendental freedom, though also (to a lesser degree) with the practical freedom which depends on it. By transcendental freedom (which he identifies with absolute spontaneity of action), Kant has in mind, “a special kind of causality in accordance with which the occurrences of the world could follow, namely a faculty of absolutely beginning a state, and hence also a series of its consequences” (A 445/B 473). Practical freedom is “the will’s [as in Willkür] independence of coercion through sensuous impulses”; more positively, it is in reference to practical freedom that Kant says: “[i]n the human being there is a faculty of determining oneself from oneself, independently of necessitation by sensible impulses” (A 534/B 562). Kant’s antinomies present arguments for two contradictory positions, illustrating the contradictions into which reason falls when it fails to recognize its own bounds. The Third Antinomy concerns freedom and natural necessity. The thesis claims that the explanation of appearances (i.e., the world and its objects insofar as they are objects of possible experience for us) requires the assumption of a causality of freedom in addition to a causality in accordance with natural laws. The antithesis claims that there is no freedom, and that causation occurs only in accordance with laws of nature. There are equally compelling—but on the face of it, contradictory—arguments for both the thesis and the antithesis (A 444–51/B 472–79). Kant’s solution is to argue that freedom and determinism are not impossible to reconcile, if we posit two different points of view (standpoints): the standpoint he associates with the intelligible (or noumenal) world, according to which we are wholly independent of causal laws and instead subject to our own laws, and the standpoint he associates with the sensible (or phenomenal) world, according to which we are determined according to natural causal laws.

[I]f that which must be regarded as appearance in the world of sense has in itself a faculty which is not an object of intuition through which it can be the cause of appearances, then one can consider the causality of this being in two aspects, as intelligible in its action as a thing in itself, and as sensible in the effects of that action as an appearance in the world of sense. (A 538/B 566)

Kant even suggests that natural causal laws are themselves an effect of intelligible causation.

Kant maintains that the human will has an empirical character that can be studied, and is properly thought of as the empirical cause of our actions. But he thinks that the way we impute blame to others suggests that we think of rational beings as free to act rightly regardless of the natural causes that we can point to in order to explain their wrong actions, and thus are free (A 554–55/B 582–83). Moreover, our consciousness of moral imperatives leads us to recognize our freedom (rational causality), or at least to recognize our representation of ourselves as having rational causality (A 547/B 575). In sum, as long as one takes up both perspectives, “freedom and natural necessity can exist in one and the same action” (A 557/B 585). It is important to note, however, that Kant recognizes that it is impossible for us to say much of anything about the intelligible world itself, or how it underlies the sensible world. Moreover, Kant issues the explicit caveat that he has not been able to “establish the reality of freedom as a faculty that contains the causes of appearance in our world of sensible” or even “to prove the possibility of freedom.” He has been treating freedom “only as a transcendental idea” by which reason is led to think of its ability to begin a series of events in the sensible world. To show “that nature at least does not conflict with causality through freedom—that was the one single thing we could accomplish, and it alone was our sole concern” (A 557–58/B 585–86).

Kant’s main argument concerning freedom in the Groundwork takes place in section III, where he seeks to establish the supreme moral principle by showing that the categorical imperative is valid for rational agents. This argument has two main premises: that the moral law is the law of the free will, and that rational beings must regard themselves as free; the conclusion is that rational beings must regard themselves as subject to the moral law (G 4:446–48) (see Korsgaard 1996, ch. 6). Kant first defines the will “as a kind of causality of living beings insofar as they are rational” (G 4:446). After explaining the negative conception of freedom as a will’s ability to bring about effects in the world without itself being determined by “alien causes,” he argues that any negatively free will must also be free in the positive sense, i.e., autonomous. A will must have a law, since the very concept of cause implies a law-governed relation between cause and effect. A negatively free will cannot be heteronomous; so it must be autonomous. The discussion of autonomy in section two of the Groundwork already identifies autonomy with morality and the principle of autonomy with the moral law; so the moral law is the law of the free will. Next, Kant argues that all rational beings invariably and unavoidably act “under the idea of freedom” and so “in a practical respect are really free” (G 4:447–48). They must ascribe this freedom to all other rational beings as well as to themselves. So, since we inevitably ascribe freedom to ourselves, and since the moral law is the law of the free will, we must take ourselves to be bound by the moral law. Kant follows up this argument with one that concerns the interest we take in the moral law, and an apparent circle in Kant’s account of it. Here Kant argues that our membership in the intelligible world—revealed by reason’s spontaneity in its theoretical employment as well as its practical employment—shows us that we are autonomous, and that the moral law “interests [us] because it is valid for us as human beings, since it arose from our will as intelligence, and so from our proper self; but what belongs to mere appearance is necessarily subordinated by reason to the constitution of the thing in itself” (G 4:461).

In the second Critique, Kant contrasts the negative sense of freedom (independence of sensible determination) with the positive sense (self-legislation or autonomy); describes autonomy as “determination of choice through the mere form of giving universal law that a maxim must be capable of” and calls it “the sole principle of all moral laws and of duties in keeping with them”; and argues that only autonomy can establish moral obligations (CPrR 5:33). Kant describes transcendental freedom as “independence of the natural law of appearances in their relations to one another, namely the law of causality” and “independence from everything empirical and so from nature generally” (CPrR 5:29, 97). He describes practical freedom as “independence of the will from anything other than the moral law alone” (CPrR 5:94). In contrast to the Groundwork III argument from freedom to the validity of the moral law, the second Critique argues that our “direct consciousness” of the moral law grounds our conception of ourselves as free: Our consciousness of our ability to do what we judge that we ought to, in spite of temptations to act otherwise, makes us conscious of our freedom (CPrR 5:30). In the Dialectic, Kant argues that freedom “considered positively (as the causality of a being insofar as it belongs to the intelligible world),” along with the immortality of the soul and the existence of God, is a postulate of pure practical reason, belief in which is demanded (though not as a moral duty) in order to make sense of the moral law’s commands (CPrR 5:132). We cannot rationally regard the moral law as issuing duties to us unless we take ourselves to be free—in whatever way is necessary—for us to comply with those duties. Practical postulates do not expand the scope of speculative cognition, but rather “give objective reality to the ideas of speculative reason in general (by means of their reference to what is practical) and justify its holding concepts even the possibility of which it could not otherwise presume to affirm” (CPrR 5:132). (On freedom, especially in the second Critique, see Beck 1960, ch. 11.)

Many aspects of Kant’s arguments concerning freedom have raised questions. One objection is that (at least in the Groundwork and second Critique) Kant equivocates between two conceptions of freedom—one that is necessary for moral responsibility, and one that Kant identifies with moral goodness—and as a result, is left with the embarrassing position according to which only morally good wills are morally responsible (see Sidgwick 1888; cf. Wood 1984, 78–83; see also Guyer 2009). Another concern is that (at least in Groundwork section III) the kind of freedom that Kant argues we must ascribe to ourselves as rational beings is insufficient for moral freedom (autonomy), and that Kant does not recognize this (see Allison 1990, 227–29). There also questions about the development of Kant’s theory of freedom, and the consistency of his positions and arguments, and the shifting role of freedom in Kant’s philosophy (see Schneewind 1998, chs. 22–23; Guyer 2000, ch. 3). The distinction between noumena and phenomena is without a doubt one of the most controversial aspects of Kant’s ethics—and of his philosophy as a whole. Kantians have interpreted it differently. Some have understood Kant to be making a metaphysical (or ontological) claim when he distinguishes between noumenal and phenomenal worlds. (For a recent, book-length development and defense of the two-worlds interpretation, see McCarty 2009.) Others have understood Kant to be distinguishing between only different standpoints we take, identifying the noumenal world with the practical standpoint that we take when we think of ourselves as autonomous, responsible beings, and the phenomenal world with the theoretical standpoint we take when we think of ourselves as part of the natural, deterministic, empirical world (see Beck 1960, 191–94; Korsgaard 1996a, esp. chs. 6–7). There are concerns about both. Many find the notion of two worlds metaphysically cumbersome; but some raise doubts about whether the two standpoints approach is adequate for transcendental and practical freedom (see Irwin 1984, esp. 37–38; Allison 1990; Guyer 1992, 103–107; and Wood 2005a, 99–100).

6. Reason and motivation

Hume is a moral anti-rationalist famous for his claim, “Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them” (T 2.3.3.4). He is not claiming that reason has no role in human action, but rather that its role is an auxiliary one; the motivating force behind an action must come from passion. Hume’s main arguments for the limited role of reason are found in A Treatise of Human Nature. (There is debate among interpreters about whether Hume changed his position on reason and motivation between the Treatise and the second Enquiry, as well as precisely what Hume’s understanding of the nature, extent, and significance of reason’s contribution to action is (see, e.g., Milgram 1995; Radcliffe 1997; Cohon 2008 chapters 2 and 3; and Irwin 2008 chapter 26).)

The first argument reminds us of reason’s functions regarding to relations of ideas and matters of fact, and argues that “reason alone can never be a motive to any action of the will” (T 2.3.3.1). Abstract (or demonstrative) reasoning, which involves a priori inferences and judgments pertaining to relations of ideas, cannot influence the will, but only assist us in our pursuit of an end we already have (e.g., if mathematical calculations would facilitate our achievement of our end). Probable (or causal) reasoning helps us discover cause and effect relations among objects of experience conducive to the realization of pre-selected ends, but such information about cause and effect can never motivate action on its own: “It can never in the least concern us to know, that such objects are causes, and such others effects, if both causes and effects be indifferent to us” (T 2.3.3.3). In order to be motivated to act, we must first anticipate pleasure or pain from something. That anticipated pleasure or pain gives rise to feelings of desire or aversion for the object in question. Probable reasoning allows us to discern the causes of this object; our positive or negative feelings about the object then spread to the causes of it; and we are then motivated to pursue or to avoid them. Simply believing that one thing causes another will not motivate action; there must be a desire, fear, or other passion (T 2.3.3.2).

A second argument, which proceeds from the conclusion to the former argument, aims to show that reason “can never oppose passion in the direction of the will” (T 2.3.3.1). The only thing that can oppose an impulse to action generated by one passion is a contrary impulse. Reason, then, could counteract an impulse to action generated by a passion if and only if reason could itself generate a contrary impulse. But from the first argument, we know that that reason cannot generate such an impulse. “Thus it appears, that the principle, which opposes any passion, cannot be the same with reason, and is only called so in an improper sense” (T 2.3.3.4). Hume goes on to say that whatever we feel in us running contrary to an impulse to act that we mistake for reason must be something else, such as a calm passion (e.g., a general appetite for the good, benevolence, or aversion to evil) (T 2.3.3.8).

The third argument claims that a passion is an “original existence,” not an idea, or a mental copy of another object. Contradiction to truth and reason “consists in the disagreement of ideas, consider’d as copies, with those objects, which they represent” (T 2.3.3.5). So a passion cannot be contrary to truth and reason. Passions cannot, strictly speaking, be evaluated as reasonable or unreasonable, despite our practice of calling passions unreasonable or irrational when they depend in some way on poor reasoning or false beliefs. Later in the Treatise, Hume extends this argument to volitions and actions as well (T 3.1.1.9); we might view Kant’s conflict in conception and contradiction in will tests of the formula of universal law to constitute refutations of the latter argument (G 4:421–24) (see Guyer 2008, ch. 5).

These arguments convey Hume’s positions that passion plays the dominant role in motivating action, reason a merely subsidiary role; reason cannot control or resist passion’s motivational influence; and one cannot use the standards of reason to praise or criticize passions. Hume draws some further important, anti-rationalist moral conclusions, partly on the basis of these views and arguments on reason, passion, and motivation generally. One obvious implication is that reason cannot be the motive to moral action; if reason cannot motivate any sort of action, it cannot motivate moral action. A second further conclusion is that morality (fundamental moral principles) cannot be grounded in reason; this one follows both from his views about the “inertness” of reason generally, and from his assumption that morality is capable of motivating people: “Morals excite passions, and produce or prevent actions. Reason of itself is utterly impotent in this particular. The rules of morality, therefore, are not conclusions of reason” (T 3.1.1.6). Moreover, we can say, in keeping with the third argument, that an act’s rightness or wrongness cannot consist in its reasonableness or unreasonableness, because acts cannot, strictly speaking be reasonable or unreasonable (T 3.1.1.9). A third further conclusion is that reason cannot discover morality (or fundamental moral principles or distinctions). Virtue and vice, and other aspects of morality, are beyond the purview of demonstrative reasoning, which concerns the relations of resemblance, contrariety, degrees in quality, and proportions in quantity and number (T 3.1.1.18). And the moral goodness (for example) of an action cannot be reduced to its cause or effect, or to other matters of fact that probable (or causal) reasoning can supply (T 3.1.1.26). In sum, then, Hume argues that the source of morality, our means of discerning moral distinctions, and the spring of moral motivation, must be the passions.

For Kant, by contrast, reason not feeling is the source of morality, of moral motivation, and of our grasp of moral obligation. In Kant’s view, only if pure practical reason is the source of morality can morality categorically, necessarily, and universally, bind all rational beings:

Everyone must grant that a law, if it is to hold morally, that is, as a ground of an obligation, it must carry with it absolute necessity; that, for example, the command, “thou shalt not lie,” does not hold only for human beings, as if other rational beings did not have to heed it, and so with all the other moral laws properly so called; that, therefore, the ground of obligation here must not be sought in the nature of the human being or in the circumstances of the world in which he is placed, but a priori simply in concepts of pure reason. (G 4:389, see also 408, 411)

The example of not lying seems ill-chosen, because Kant’s own theory does not treat it as a fundamental moral requirement, but rather as a duty derived from a fundamental requirement (MM 6:429–31). Nevertheless, this passage shows how Kant’s conception of moral obligation implies that morality and its basic principles have a purely rational source.

When it comes to moral epistemology, feelings certainly have a role to play, but the role comes fairly late in the game. It is through reason that we discover basic moral principles; but judgment, experience, and cultivated feelings—all within the realm of what the average person can attain—can aid us in our use of these principles (G 4:389, 391, 403–404; MM 6:411, 456–58). For Kant, moral epistemology is not a matter of discovering an external, independently created set of moral rules, but rather recognizing a rationally self-legislated moral law. (Some commentators talk of reason’s “constructing” moral principles; see, e.g., Rawls 1980; O’Neill 1989, ch. 11; cf. Ameriks 2006, ch. 11). Kant talks of reason “commanding” what we should do, and emphasizes that we are co-legislators as well as subjects in the kingdom of ends (G 4:408, 431–45). Moreover, much of what we see Kant doing in the first two sections of the Groundwork is leading us from compelling assumptions about value and moral obligation, through arguments about the nature of rationality and the commitments inextricably linked to our rational nature, and to formulations of the categorical imperative.

Regarding moral motivation: It is a central feature of Kant’s ethics that pure reason can be practical—that reason can “of itself, independently of anything empirical, determine the will” (CPrR 5: 42). Kant says of right actions:

Such actions … need no recommendation from any subjective disposition or taste, so as to be looked upon with immediate favor and delight; nor do they need any immediate propensity or feeling for them; they present the will that practices them as the object of an immediate respect, and nothing but reason is required to impose them upon the will. (G 4:435)

Moreover, in the first section of the Groundwork, Kant repeatedly emphasizes the “moral worth” that attaches to right actions that are performed simply because they are right—i.e., actions motivated from “from duty” or “from respect for the law” (G 4:396–401) (see Timmermann, 2009).

Yet the way reason motivates finite rational beings (such as humans) to act rightly is by means of feelings. In the Groundwork, Kant focuses on respect for the law (mentioned above). Initially in the Groundwork, Kant describes respect in a manner that makes it sound like a felt aspect of the law itself: “an action from duty is to put aside entirely the influence of inclination, and with it every object of the will; hence there is left for the will nothing that could determine it the except objectively the law and subjectively pure respect for this practical law” (G 4:400). But Kant goes on to describe respect for the law in a way that makes it sound more like a separate feeling, though one arising from reason:

It could be objected that I only seek refuge behind the word respect in an obscure feeling, instead of distinctly resolving the question by a concept of reason. But although respect is a feeling, it is not one received by means of influence; it is, instead, a feeling self-wrought by a rational concept and therefore specifically different from all feelings of the first kind, which can be referred to inclination or fear. What I cognize immediately as a law for me, I cognize with respect, which signifies merely consciousness of the subordination of my will to a law without the mediation of other influences on any sense. Immediate determination of the will by means of the law and the consciousness of this is called respect, so that this is regarded as the effect of the law on the subject, and not as the cause of the law. (G 4:401 n; also see 460)

In the Critiqueof Practical Reason, Kant describes the special moral feeling of respect for the law as having both a painful aspect, involving the humiliation the agent feels as the moral law strikes down her self-conceit, and a pleasurable, ennobling aspect, since the moral law comes from her own pure reason, and represents her own higher self and vocation (CPrR 5:73). In the Metaphysics of Morals, Kant lists moral feeling, conscience, love of human beings, and respect (for oneself) as special kinds of feelings of which we are made aware only though consciousness of the moral law (MM 6:399). He describes these feelings as “moral endowments” that “lie at the basis of morality” and as “subjective conditions of receptivity to the concept of duty” (MM 6:399). Since our compliance with duty presupposes our having these feelings, there is no duty for us to have them. There is a duty to cultivate them, however, because of their moral usefulness.

Kant is explicit that feelings—especially pleasure (or satisfaction) and pain (or displeasure), both actual and anticipated—are essential to human moral motivation (see Guyer 2008, ch. 5; and Guyer 2010). In the Groundwork, Kant states: “In order for a sensibly affected rational being to will that for which reason alone prescribes the ‘ought,’ it is admittedly required that his reason have the capacity to induce a feeling of pleasure or of delight in the fulfillment of duty, and thus there is required a causality of reason to determine sensibility in conformity with its principles” (G 4:460). Even though we cannot know (or “make intelligible a priori”) how a thought or judgment about the morality of an action “can itself produce a sensation of pleasure or pain,” Kant thinks that this somehow does happen; it must, if moral considerations are to be motivating in beings like us. In the Critiqueof Practical Reason, Kant suggests that the painful feeling of having one’s self-conceit struck down is a necessary part, or perhaps condition, of moral motivation. The agent must see the moral law, not her own inclinations, as legislative for her in order to be morally motivated. By removing the “resistance,” “counterweight,” or “hindrance” to the moral law that self-conceit presents, the moral feeling of respect is, in the judgment of reason, “esteemed equivalent to a positive furthering of [the moral law’s] causality” (CPrR 5:75). And in the Metaphysics of Morals, Kant states that “Every determination of choice proceeds from the representation of a possible action to the deed through the feeling of pleasure or displeasure, taking an interest in the action or its effect” (MM 6:399; also see M 29:625–26). What is so important about respect for the law, moral feeling, and other rationally grounded feelings is that through them human beings are able to feel pleasure or displeasure solely by considering the morality of our actions.

In spite of the foregoing, Kant may nevertheless appear hostile to our natural, sensibly-grounded human emotions. In the Metaphysics of Morals “Doctrine of Virtue,” for example, he warns against the dangers of affects and passions, and urges apathy and self-mastery: “unless reason holds the reins of government in his own hands, a human being’s feelings and inclinations play the master over him” (MM 6:408). Apathy and self-mastery are essential for expressing and protecting inner freedom, which can be threatened by affects and passions. Affects [Affekte] are emotional agitations, sudden, fleeting emotions that temporarily interfere with rational reflection and self-control (Ant 7:253, 267; MM 6:407). Passions [Leidenschaften] are more persistent, stable inclinations that continually tempt us to satisfy them, even when we know that it is wrong to do so. Kant gives anger as an example of an affect, hatred as an example of a passion (MM 6:408). In praising moral apathy, Kant advocates not an insensibility but a resistance to affect, and in particular, a refusal to determine one’s will in accordance with whatever strong, fleeting feelings one happens to have. Self-mastery is more comprehensive than apathy, and includes resistance to passions. Self-mastery involves an agent’s “bring[ing] all his capacities and inclinations under his (reason’s) control and so to rule over himself” (MM 6:408). In urging self-mastery, Kant recommends not that one rid oneself of feelings and inclinations, but that one use them in ways that are compatible with—and perhaps even conducive to–morality. We are not completely passive with regard to our emotions; they respond to our cultivation, and so are in part products of our choices (Ant 7: 254; MM 6:402).

Indeed, Kant clearly sees moral value in some sensibly-grounded (“pathological”) feelings as well as special rationally grounded ones discussed above. Certain emotions are naturally-given feelings that we can use in the fulfillment of our duties, and which we therefore have a duty to cultivate (MM 6:456–57, 458; also M 29:626; NF 19:77 #6560). Speaking of sympathy, which is perhaps the best example of this sort of feeling, Kant says, “it is … an indirect duty to cultivate the natural … feelings in us, and to make use of them as so many means to sympathy based on moral principles and the feeling appropriate to them” (MM 6:457). According to Kant, sympathy allows us better to understand others’ needs, helps us to communicate our concern for them, and can act as an additional incentive to facilitate our promotion of our happiness helping others. Such sensibly-grounded feelings can work with rationally-grounded feelings in order to motivate us to act morally. We may cultivate sympathetic feelings from respect for the law, and then find these feelings prompting us to act in certain ways. Of course, however sympathetically motivated these actions are, their maxims must be morally permissible—something that cannot be guaranteed even when the sympathy that motivates has been cultivated out of respect for the law or the rationally-grounded feeling of love of one’s neighbor.

To conclude: Both Kant and Hume assume that moral considerations motivate action. Moreover, they appear to share a view of human action according to which feelings—especially feelings of pleasure and pain—are needed for motivating action. For Hume, of course, this view of human action is all that is needed or warranted; and in his version, passions take the leading role, reason the supporting one. For Kant, by contrast, the story of human action featuring feelings such as respect for the law, moral feeling, and sympathy, comes as an addition to his a priori story about the moral law’s being grounded in reason; and in Kant’s story, reason plays the dominant role in moral motivation and moral epistemology. The motivational roles Kant gives to feelings reflect his empirical moral psychology, not his metaphysics of freedom (Guyer 2008, ch. 5; and Guyer 2010). Moreover, the feelings that Kant sees as most crucial to moral motivation (respect for the moral law, respect for rational nature, moral feeling) are themselves rationally-grounded, reflecting the immediate effect of the moral law on our sensibility. The “pathological” feelings that we have indirect duties to cultivate are of genuine, but conditional, moral value.

A final contrast to note is that Hume would adamantly reject Kant’s attribution of a special moral value, “moral worth,” to actions done “from duty.” According to Hume, “no action can be virtuous, or morally good, unless there be in human nature some motive to produce it, distinct from a sense of its morality” (T 3.2.1.7). The motive of acting virtuously cannot be the standard or basic motive to virtuous action, since, according to Hume, what makes an act virtuous is its expression of a virtuous motive, which in turn reflects a virtuous quality of character (T 3.2.1.2). To avoid circularity, there must be a motive to virtuous action that does not itself refer to the moral goodness of the act (T 3.2.1.4). For Hume, the only time one would have to rely on one’s sense of the rightness or virtuousness of an act to motivate oneself to do it is when one finds oneself deficient in the natural feelings that ordinarily prompt people to act morally (e.g., natural affection, generosity, gratitude). In such a case, one may feel humility (or even self-hatred) due to one’s defect, and consequently form a desire to change one’s conduct (and perhaps even one’s character). As we have seen, however, on Kant’s scheme, the most pure or direct kind of moral motivation is motivation from duty or from respect for the law. Yet Kant often expresses doubt that there have ever been human actions motivated from duty alone (e.g., G 4:406–407). And, as discussed above, Kant’s more mature writings on normative ethics acknowledge that respect for the law works in conjunction with and even to some degree through other feelings. Although important, Kant’s notion of moral worth must be understood in the context of the Groundwork I argument from the idea of an unconditionally good will to the first, rough formulation of the categorical imperative. We should not confuse Kant’s concepts of the good will and moral worth in Groundwork I with his conceptions of virtue and the virtues that emerge in his more mature, normative works.

7. Virtues and vices

According to Hume, “morality is determined by sentiment” and virtue is “whatever mental action or quality gives to a spectator the pleasing sentiment of approbation” (EPM App.1.10); “virtue … is a quality of the mind agreeable to or approved by everyone, who considers or contemplates it” (EPM 8n50). Our moral judgments, then, are best understood as deliverances of sentiment or feeling. The particular sentiments or feelings in question are those of approval or disapproval. They are usually (though not always) calm passions. The sentiment of approval is a kind of pleasure; of disapproval, a kind of pain. The characteristic object of our moral judgment, or what stimulates our sentiments, is a character trait of oneself or someone else. Character traits themselves are stable dispositions to feel—and thus to be moved to act—in certain ways. We usually judge acts as virtuous or vicious based on our assessment of the traits that we think motivate them. The basis for our approval or disapproval, Hume thinks, is the agreeableness or usefulness of the trait in question. Although each trait is assessed based on its usefulness or agreeableness both to the possessor and others, the standpoint from which one makes this assessment is a general one. Moral assessors take up a “common point of view” from which the assessor can appreciate how everyone who is affected by the object of evaluation (e.g., a character trait of a particular person) is affected by it. (See Cohon 2008, chapters 3, 4, and 8; Irwin 2008, chapter 58; and Korsgaard 2008, chapter 9.)

The process of moral assessment from this common point of view fundamentally involves sympathy, understood not as one among various sentiments such as pity or benevolence, but as a psychological mechanism through which one person can “enter into the same humor, and catch the sentiment” of another (EPM 7.2). Sympathy allows us “to receive by communication their inclinations and sentiments, however different from, or even contrary to our own” (T 2.1.11.2). Because human beings greatly resemble each other, we easily recognize others’ sentiments; this recognition leads us to “enter into” their sentiments. The greater the resemblance we recognize between ourselves and someone else, or the stronger the contiguity between us or our experiences to them or theirs, the easier it is for our imagination to convey their feelings to us, and the more vivid our sense of those feelings (T 2.1.11.5). One interesting thing about the operation of sympathy for Hume is that not only do we form an idea of the feeling of another, but this idea transforms into an impression:

[W]hen we sympathize with the passions and sentiments of others, these movements appear at first in our mind as mere ideas, and are conceiv’d to belong to another person, as we conceive any other matter of fact. ‘Tis also evident, that the ideas of the affections of others are converted into the very impressions they represent, and that the passions arise in conformity to the images we form of them. (T 2.1.11.8)

In most of Hume’s account of impressions and ideas, ideas are fainter copies of the impressions which precede them; yet here we have ideas giving rise to vivid impressions.

Now the fact that we have more resemblances to and relations with some people than others, and hence find it easier to sympathize with some than others, might suggest that moral judgment cannot rest on sympathy, since our moral approbation, unlike our personal preference, is not (or at least is not supposed to be) biased in favor of those to whom one is most similar or closest. Part of Hume’s response to this objection is to say that we can “correct our sentiments” (or at least our language) if “we fix on some steady and general points of view; and always, in our thoughts, place ourselves in them, whatever may be our present situation” (T 3.3.1.15). That is, if we take up an unbiased point of view, allowing ourselves to share the feelings of everyone affected by the person, trait, or action in question, our approval or disapproval of the object will be grounded in sympathy, but not be biased or fluctuating depending on our individual, changing relationships and circumstances.

In the Treatise, Hume divides virtues into natural and artificial ones. Artificial virtues depend on convention, contrivance, or rule-following (T 3.2.6.3–4). Their social utility may not be evident when a single act exhibiting an artificial virtue is committed in isolation. Rather, the beneficial nature of these virtues requires their being pervasively and consistently expressed throughout a society in accordance with a general rule (T 3.2.2.10). Artificial virtues are not arbitrary, however. They are necessary human inventions in response to the demands of broad social interaction (T 3.2.1.19). Natural virtues, on the other hand, have no need of rules or conventions for them to be useful or pleasing; additionally, they are useful or pleasing on each occasion (T 3.3.1.12). Among the artificial virtues, Hume includes justice, fidelity to promises, allegiance to government, obedience to laws of nations, chastity, and modesty. (See Cohon 2008, chapters 6 and 7; and Irwin 2008, chapter 59.)

In Book III, Part 3, Hume devotes much discussion to justice, which he seems to regard as a paramount and paradigmatic artificial virtue. Hume understands justice primarily as honesty with respect to property or conformity to conventions of property (T 3.2.2.28). Establishing a system of property allows us to avoid conflict and enjoy the possession and use of various goods, so the social value of conventions involving property seems obvious. Yet one reason that justice receives such attention from Hume is that it poses a problem about moral motivation and moral approval. Hume claims that there needs to be a natural (non-moral) motive for morally good actions, for otherwise they could only be done because they are morally good; and that would be circular, since our judgment of acts as morally good reflects our approval of the motives and traits that give rise to the acts in question (T 3.2.1.7, 3.2.1.17). But this position makes it hard to see how justice can be a virtue; for it is hard to find the requisite natural, nonmoral motive for it. Self-interest is the natural motive that justifies our establishing rules regarding property (T 3.2.2.24); but self-interest is neither always satisfied by just acts, nor approved in the way that traits we call virtues generally are (T 3.2.1.9–10). Neither public nor private benevolence would do, since neither could motivate all just actions (T 3.2.1.12). Hume himself says that “a sympathy with public interest is the source of the moral approbation, which attends that virtue” (T 3.2.2.24). But since sympathy with the public interest itself seems neither nonmoral nor inherent in human nature, this claim redescribes the problem rather than solves it. Hume must ground sympathy for the public interest in more obviously natural sentiments, and explain its development from them (e.g., as self-interest, corrected or redirected through education or the contrivances of politicians). Otherwise, Hume must abandon his claim that all morally good actions—even those associated with artificial virtues—have non-moral, natural motives. (See Gauthier 1979; Mackie 1980, ch. 5; and Darwall 1995, 302–316).

Among the natural virtues, Hume includes beneficence, prudence, temperance, frugality, industry, assiduity, enterprise, dexterity, generosity, and humanity (T 3.3.1.24). In An Enquiry Concerning the Principles of Morals, he distinguishes among virtues useful to others, virtues useful to oneself, virtues immediately agreeable to oneself, and virtues immediately agreeable to others. Among qualities useful to others are justice, fidelity, honor, allegiance, chastity, along with the other “social virtues” of humanity, generosity, charity, affability, lenity, mercy, and moderation (EPM 5.2.44). Among qualities useful to ourselves are discretion, caution, enterprise, industry, assiduity, frugality, economy, good sense, prudence, discernment (EMP 6.1.21). Among qualities contrary to our own well-being are indolence, negligence, “want of order and method,” obstinacy, fickleness, rashness, and credulity (EPM 6.1.1). Qualities immediately agreeable to oneself include cheerfulness, tranquility, benevolence, and delicacy of taste. Qualities immediately agreeable to others include good manners, politeness, wit, ingenuity, decency, cleanliness, and a graceful or genteel manner. What holds all these varied traits together as virtues is their evoking the sentiment of approval in spectators, itself grounded in sympathy.

A few more points about Hume’s account of the virtues are worth mentioning. Hume blames “superstition and false religion” for the misguided view some have that the “monkish virtues” of celibacy, fasting, penance, mortification, self-denial, humility, silence, and solitude are virtues; they are, instead, vices (EPM 9.1.3). When it comes to women, however, Hume does consider chastity, modesty, decency, and reserve essential virtues (EPM 6.1.14; T 3.2.12). Some of the traits that Hume considers virtues, such as cheerfulness, wit, or good memory, seem neither specifically moral, nor much within the agent’s control. They seem more to be a matter of non-moral talent or natural ability. In fact, Hume explicitly challenges the significance of the distinction between moral virtue and natural ability (T 3.3.4). For Hume, as long as a quality of a person is pleasing or useful, so as to give rise to the sentiment of moral approval in those considering it from the general point of view, it is a virtue. Moreover, Hume views all of our traits as effects of natural causation; and he takes virtues to be the sorts of traits that commonly and naturally arise among human beings—not as rare qualities that have to be arduously cultivated. Hume claims that it is extremely difficult for people to make any substantive change in their characters, though he thinks we may have some success in altering our conduct (e.g., by refraining from certain behaviors out of a desire to avoid moral disapproval from ourselves or others) (T 3.2.1.8, 3.3.4.3).

On Kant’s conception of virtue, virtue is the form in which a being with a non-holy will expresses her supreme commitment to morality. Virtue is such a being’s continually cultivated capacity to master her inclinations so as to fulfill her duties; a capacity whose cultivation and exercise is motivated by respect for the moral law. This account of Kant’s conception of virtue is grounded in six related theses about virtue that Kant advances. (The discussion below draws on Denis 2006; for a more recent, book-length account of Kant’s theory of virtue, see Baxley 2010.)

First, virtue is a disposition to comply with the moral law (i.e., to do one’s duty) do one’s duty out of respect for the moral law (CPrR 5:128, 160; C 27:300). Second, virtue is a kind of strength. Kant defines virtue as “the concept of strength” (MM 6:392, 390; Rel 6:57; V 27:429). Specifically, virtue is “a moral strength of the will” (MM 6:405), “moral strength in adherence to one’s duty” (Ant 7:147). Third, virtue presupposes opposition and entails struggle, and thus—fourth—is a feature of non-holy (e.g., human) wills (CPrR 5:84). Kant calls virtue “the capacity and considered resolve to withstand a strong but unjust opponent … with respect to what opposes the moral disposition within us” (MM 6:380). Human beings do not have holy wills, “whose maxims are necessarily in accord with laws of autonomy (the moral law)” (G 4:439); if we did, we would act rightly without moral obligation or struggle. Kant often seems to identify our inclinations as the primary opponents of morality (G: 4:405; V 27:450, 492; C 27:450). His considered view, however, is that inclinations are not the source of the problem. Virtue’s primary opponent is “radical evil in human nature”—a propensity to give self-love (and inclinations generally) priority over the moral law in our maxims (Rel 6:29, 35–37, 57 n., 58). It is because of radical evil that virtue implies struggle and demands strength. The fundamental task of the virtuous person is to achieve the proper ordering of her incentives, giving the moral law undisputed priority over self-love within her supreme maxim. Fifth, virtue is moral self-constraint “based on inner freedom” (MM 6:408), which is the capacity to act on the autonomously chosen principles of morality, even in the face of temptation (MM 6:394, 405). Virtue both expresses and promotes inner freedom. The greater one’s moral self-constraint (i.e., one’s virtue), the more one acts based on reason, and the less one acts based on inclination or impulse (MM 6:382 n). Finally, sixth, virtue can be understood either as “phenomenal virtue,” “a facility in actions