Hume writes in his autobiographical essay, “My Own Life,” that he regarded his Enquiry concerning the Principles of Morals as “of all my writings, historical, philosophical, or literary, incomparably the best.” This work, like the Enquiry concerning Human Understanding, was a part of his Treatise on Human Nature that he had decided to “cast anew” (MOL 9-10). In an advertisement composed late in his life, Hume wrote that the volume of essays that included these two works afforded him an opportunity to correct “some negligences in his former reasoning and more in the expression” of the Treatise, and that he wanted the later work, and not the Treatise, to be “regarded as containing his philosophical sentiments and principles.” The second Enquiry is often considered amore eloquent work than the Treatise. But Hume's correction of some “negligences” in reasoning, the addition of new arguments, and a restructuring of main themes give the later work a philosophical significance in its own right.

This essay examines Hume’s later moral philosophy. I also look at some differences between the Treatise and his later works. But the main aim of the essay is to draw attention to what makes the later work philosophically interesting and important in comparison with Hume’s earlier work. In particular, I show the importance of the mature Hume’s attention, in the second Enquiry, “A Dialogue,” and some of his essays, to the role of language and reason in morality. He also has important things to say about the issue of the universality and relativity of morals.

Hume's observations on the arts are set in the framework of social life. That is why he considers both the making of, and response to, works of art as human actions subject to the analysis he has offered of other human actions. He never published his intended treatise on “criticism” (T Adv.), and no developed theories of beauty, art, or criticism are to be found in his works. But by bringing together his scattered remarks on these subjects, and by looking at his general aims and the context in which he wrote, we can identify his principal views on these topics.

Cultural Context

It is always important to establish the context and date of a writer's views; it is especially important when setting out Hume's ideas on what today we call aesthetics. His interests and references, in almost every respect except the crucial one of classical literature, were narrower than those of an informed modern reader. We need to know what he might, and what he could not, have experienced, and to recognize that his cultural environment differed essentially from ours: concepts of, and attitudes to, the various mediums of art in the 1740s were evolving rapidly, as were artistic practices and expectations. Excepting only the very rich, and their households, most Scots and the majority of the English had very limited access to what count as the arts today.

David Hume's essays were “the cradle of economics,” suggested John Hill Burton, in his important biography of Hume. Although this may be a biographer's exaggeration, there can be no doubt that Hume's work provided an important contribution to political economy as a discipline, together with a significant critique of the “mercantile” system that was later attacked by his friend Adam Smith.

ECONOMICS: THE BACKGROUND

Mercantilism is difficult to define. As the historian P.J. Thomas put it: “Mercantilism has often been described as a definite and unified policy or doctrine, but that it has never been. In reality it was a shifting combination of tendencies which, although directed to a common aim - the increase of national power - seldom possessed a unified system of policy, or even a harmonious set of doctrines. It was a very complicated web of which the threads mingled inextricably.” In the seventeenth and eighteenth centuries the object of policy was the enhancement of the power of the nation state, a strategy that was to be attained in a number of ways, at least one of which was economic. The power of this state was to be enhanced by the accumulation of treasure through trade, the maximization of employment, and the encouragement of population growth.

Hume's theory of causation is one of the most famous and influential parts of his philosophy. When compared with the accounts provided by earlier philosophers whom Hume studied, such as René Descartes (1596-1650), John Locke (1632-1704), and Nicolas Malebranche (1638-1715), his theory is revolutionary. It is also controversial, and has been interpreted in a number of different ways. This is not surprising, because Hume's ideas about causation are not only challenging in themselves, but also lie at the heart of much of the rest of his thought. As a result, interpretations of Hume on causation influence, and are influenced by, interpretations of his general philosophical aims, methods, and purposes.

Hume's account of causation is part of his theory of human nature or “science of man.” The theory is a partly epistemological, partly psychological investigation of how human beings acquire beliefs and knowledge, make moral, political, and aesthetic judgments, and act in and react to the natural and social world. Hume's approach to these questions is genetic. He sets out to identify the origins of thoughts, feelings, judgments, and patterns of behavior and response. His theory of causation, therefore, is not primarily a metaphysical account of what causality consists in, although it has implications for that. Rather, it is an investigation of two main questions. First, how do human beings come to have the idea of causation? Second, how do human beings come to be able to infer effects from causes and causes from effects?

Hume's critique of religion and religious belief is, as a whole, subtle, profound, and damaging to religion in ways that have no philosophical antecedents and few successors. Some of the damage and a little of the subtlety will, I trust, become evident in Part II of this essay, where Hume's seminal discussions of the design argument for the existence of God, miracles, morality, and natural belief are examined. Before this, however, certain preliminaries need attention. First, there is the difficulty caused by the old-fashioned or unfamiliar terminology used by Hume and his commentators in describing and assessing what he has to say. Second, although the scale of Hume's writing on religion is reasonably obvious (it exceeds his output concerning any other subject except history), the fact that it is dispersed over a number of publications and partly embedded (sometimes none too clearly) in several more, as well as having to be drawn from essays, letters, and minor writings, needs to be understood before any informed discussion is possible. Third, there is the problem of seeing what he wrote not as ad hoc criticisms turned out piecemeal, but as a comprehensive critical strategy. Finally, a problem of interpretation results from Hume's “abundant prudence” in covering his real opinions with ambiguous irony and even, on occasions, with denials of his own apparent conclusions.

The first volume of Hume's History of England, dealing with the early Stuarts, appeared in 1754. The final volumes, covering the period from the invasion of Julius Caesar to 1485, appeared in 1762, although Hume was occupied with revisions of the whole work until his death. In writing history, Hume was partly creating, partly responding to, a new market. In 1757 he thought history “the most popular kind of writing of any” (HL 1:244). In 1770 he wrote, “I believe this is the historical Age and this [Scotland] the historical Nation” (HL 2:230). He knew of no fewer than eight histories that were currently being written. The year before, in England, he had declared, “History, I think, is the Favourite Reading” (HL 2:196). Hume and his friend William Robertson were in large part responsible for this new popularity of history, much of it written by Scotsmen for English readers. Hume himself had received unprecedented payments for his History (for which he sold the copyright on each volume, rather than collecting royalties): he made at least £3,200 on the whole, at a time when a friend of his could consider himself well to do on £80 per annum (HL1:193, 255, 266, 314). Although in practice his History seems to have sold less well during his lifetime than the various volumes of his Essays, Hume was consistently of the opinion that this was his bookseller's fault. The market for history books was potentially far larger (HL 2:106, 229, 233, 242).

In Treatise 1.2, Of the ideas of space and time, Hume examines our ideas of spatial extension and temporal duration, our ideas of geometric equality, straightness, flatness, and mathematical point, and our ideas of a vacuum and of time without change. Hume does not, however, restrict his attention to these ideas; he also draws conclusions about space and time themselves. He argues that space and time are not infinitely divisible, that their smallest parts must be occupied, and that as a consequence there is no vacuum or interval of time without change. His treatments of matters beyond the scope of the section's title have received harsh criticism. His conclusions have seemed contrary to mathematics and physics. His method of arguing - applying features of our mere ideas of space and time to space and time themselves - has seemed philosophically inept. The apparent success of these criticisms has led to widespread neglect of this part of Hume's work.

The neglect is unfortunate. In Of the ideas of space and time Hume gives important characterizations of the skeptical approach that will be developed in the rest of the Treatise. When that approach is better understood, the force of Hume’s arguments concerning space and time can be appreciated, and the influential criticisms of them can be seen to miss the mark.

BACKGROUND

The problem of personal identity, as philosophers understand it today, emerged from the discussion of identity that Locke added to the second edition of The Essay concerning Human Understanding, published in 1694. In the forty-five years between the publication of that work and the publication of the Treatise, the literature on the problem of personal identity mushroomed, prompting Hume to observe wryly: “We now proceed to explain the nature of personal identity, which has become so great a question in philosophy, especially of late years in England, where all the abstruser sciences are study'd with a peculiar ardour and application” (T 1.4.6.15). Hume's own explanation of the nature of personal identity drew on the resources of his accounts of the imagination and the passions, and was therefore unique in many respects. Nevertheless, the debates of the preceding decades had covered considerable ground, and the distinctive features of Hume's own view emerge more clearly when seen in the context of what had come before.

Locke added the chapter Of Identity and Diversity to the second edition of his Essay to address issues about personal identity that arose from his arguments against the Cartesian view that the soul always thinks. Locke’s basic assumption was that questions about identity had to be understood in relation to the kind of object under consideration: one and the same object could instantiate different kinds, each of which would have different conditions of identity.

For Hume, understanding the workings of the mind is the key to understanding everything else. There is a sense, therefore, in which to write about Hume's philosophy of mind is to write about all of his philosophy. With that said, I shall nonetheless focus here on those specific doctrines that belong to what we today call the philosophy of mind, given our somewhat narrower conception of that subject. It should also be remembered that Hume describes his inquiry into the nature and workings of the mind as a science. This is an important clue to understanding both the goals and the results of that inquiry, as well as the methods Hume uses in pursuing it. As we will see, there is a thread running from Hume's project of founding a science of the mind to that of the so-called cognitive sciences of the late twentieth century. For both, the study of the mind is in important respects just like the study of any other natural phenomenon. While it would be an overstatement to say that Hume's entire interest lies in the construction of a science in this sense - he has other, more traditionally “philosophical,” concerns - recognizing the centrality of this scientific aim is essential for understanding him.

By the time Hume started to work on his Treatise, the notion of an idea as the primary, most general sort of mental item dominated European philosophy. Although Descartes noted that, strictly speaking, only those “thoughts that are as it were images of things” were appropriately described as ideas, in practice he used “the word 'idea' to refer to whatever is immediately perceived by the mind.” Not only do we have ideas of trees and the sun, but we also have ideas of our own activities of thinking and willing. Locke characterizes “idea” as “being that Term, which, I think, serves best to stand for whatsoever is the Object of the Understanding when a Man thinks.” Locke also thinks that we not only have ideas that derive from things or objects in the world (ideas of sensation), but also of the activities and operations of our own minds (ideas of reflection). Ideas of sensation are acquired through the operation of external objects on our sense organs, while ideas of reflection come from introspection, from thinking about what happens within our own minds. He also thinks that these ideas of reflection are of two basic sorts of mental activity, perception and willing, that correspond to two faculties of mind: the understanding (or the power of thinking) and the will (or the power of volition).

David Hume believed that most of the views about society and politics prevalent in his day had roots in one or another of “two species of false religion,” superstition and enthusiasm. Both were developments of conflicting theological doctrines that appealed to two different types of personalities. Both had come to be associated with opposing political interests. Both sprang from ignorance. And, while the two species had been universally present in society and in individuals in varying degrees throughout history, the peculiarity of modern post-Reformation Europe was the violent oscillation between them, as evidenced by them any wars of religion. Their more extreme adherents were also, not least, responsible for the plight of modern Britain, both north and south. One of the tasks of the philosophical historian, Hume believed, was to explain the preponderance at particular times of one or the other of these persuasions. The task he set for his political theory was to explain why both were philosophically misconceived, empirically untenable, and, in their extreme forms, politically dangerous.

THE POLITICS OF RELIGION

One part of humanity, Hume notes, has a tendency to “weakness, fear, [and] melancholy, together with ignorance.” In this state the imagination conjures up forces operating under the surface, and the mind is prone to grasp methods of influencing these forces by “ceremonies, observances, mortifications, sacrifices, presents, or [by] any practice, however absurd or frivolous which either folly or knavery recommends to a blind and terrified credulity.”

Much of what David Hume said about a wide range of subjects remains of great importance today. In the first volume of his first work, A Treatise of Human Nature, a work in which he articulated a new “science of human nature,” Hume focused on an interrelated set of issues in theory of knowledge, metaphysics, and philosophical psychology. More particularly, he explained how it is that we form such important conceptions as space and time, cause and effect, external objects, and personal identity. At the same time, he offered an equally important account of how or why we believe in the objects of these conceptions - an account of why we believe that causes are necessarily connected to effects, that there are enduring external objects, and that there are enduring selves - even though the human mind is unable to provide a satisfactory proof that these phenomena exist. In the second volume of the Treatise Hume expanded his account of human psychology, focusing on the origin and role of the passions and the nature of human freedom. In the third and final volume of this work he explored the origins and nature of morality. In later works he returned to many of these philosophical issues, but he also made substantial contributions to our understanding of political theory, aesthetics, economics, and philosophy of religion. In addition, he wrote an influential, six-volume History of England, a work published in over 175 editions in the eighteenth and nineteenth centuries, and still in print.

In Book 2 of the Treatise of Human Nature Hume reports that a question concerning the foundation of moral distinctions had “of late years” been of great public interest. The question is whether “moral distinctions” (distinctions between virtue and vice) are “founded on natural and original principles,” or arise “from interest and education.” He then suggests that those who traced the distinction between virtue and vice to “self-interest or the prejudices of education” supposed that morality has “no foundation in nature.” In contrast, those who said that moral distinctions are founded on natural and original principles supposed that “morality is something real, essential, and founded on nature” (T 2.1.7.2-3, 5). This debate, as we will see, raised both an ontological question (which features of the world, if any, do our moral judgments reflect?) and an epistemological question (which of our faculties, reason or sense, enables us to grasp moral distinctions?).

The above passage comes from a pamphlet written by David Hume to secure a readership for his largely unappreciated Treatise of Human Nature. Although not successful in this regard, the Abstract remains a valuable guide to Hume's Treatise, through offering his own assessment of the significance of that work. Here, at least, Hume is unequivocal in describing his philosophy as “very sceptical.” But even if Hume describes his philosophy in this way, and even if, at the time, his philosophy was almost universally taken in this light, it remains unclear, first, what this skepticism amounts to and, second, how this skepticism is related to other aspects of his philosophical program.

A KIND OF HISTORY OF MY LIFE

Sir

[1] Not being acquainted with this hand-writing, you will probably look to the bottom to find the Subscription, & not finding any, will certainly wonder at this strange method of addressing to you. I must here in the beginning beg you to excuse it, & to perswade you to read what follows with some Attention, [and] must tell you, that this gives you an Opportunity to do a very good-natur’d Action, which I believe is the most powerful Argument I can use. I need not tell you, that I am your Countryman, a Scotchman; for without any such tye, I dare rely upon your Humanity, even to a perfect Stranger, such as I am.

In 1927 A. E. Taylor concluded his Leslie Stephen Lecture on “David Hume and the Miraculous” with a judgment of Hume's attitude to his philosophical work that has been held by many other readers of Hume:

Taylor is here expressing an attitude to Hume that many of us have felt: that his philosophy does not deserve to be taken too much to heart, because for all his intellectual vitality and the disturbing character of much that he says, there is a streak of frivolity in him that leads him to follow arguments to outrageous conclusions without serious consideration of the effect such conclusions may have on those who are driven to them; and that the love of literary reputation that he openly expressed was of far greater personal importance to him than philosophical truth.