(1711–76), Scottish philosopher and historian who may be aptly considered the leading neo-skeptic of the early modern period. Many of Hume’s immediate predecessors (Descartes, Bayle, and Berkeley) had grappled with important elements of skepticism. Hume consciously incorporated many of these same elements into a philosophical system that manages to be both skeptical and constructive.
Born and educated in Edinburgh, Hume spent three years (1734–37) in France writing the penultimate draft of A Treatise of Human Nature. In middle life, in addition to writing a wide-ranging set of essays and short treatises and a long History of England, he served briefly as companion to a mad nobleman, then as a military attaché, before becoming librarian of the Advocates Library in Edinburgh. In 1763 he served as private secretary to Lord Hertford, the British ambassador in Paris; in 1765 he became secretary to the embassy there and then served as chargé d’affaires. In 1767–68 he served in London Page 399 | Top of Articleas under-secretary of state for the Northern Department. He retired to Edinburgh in 1769 and died there.
Hume’s early care was chiefly in the hands of his widowed mother, who reported that young David was “uncommon wake-minded” (i.e., uncommonly acute, in the local dialect of the period). His earliest surviving letter, written in 1727, indicates that even at sixteen he was engaged in the study that resulted in the publication (1739) of the first two volumes of A Treatise of Human Nature. By the time he left college (c.1726) he had a thorough grounding in classical authors, especially Cicero and the major Latin poets; in natural philosophy (particularly that of Boyle) and mathematics; in logic or theory of knowledge, metaphysics, and moral philosophy; and in history. His early reading included many of the major English and French poets and essayists of the period. He reports that in the three years ending about March 1734, he read “most of the celebrated Books in Latin, French & English,” and also learned Italian. Thus, although Hume’s views are often supposed to result from his engagement with only one or two philosophers (with either Locke and Berkeley, or Hutcheson or Newton), the breadth of his reading suggests that no single writer or philosophical tradition provides the comprehensive key to his thought.
Hume’s most often cited works include A Treatise of Human Nature (three volumes, 1739–40); an Abstract (1740) of volumes 1 and 2 of the Treatise; a collection of approximately forty essays (Essays Moral, Political, and Literary, first published, for the most part, between 1741 and 1752); An Enquiry concerning Human Understanding (1748); An Enquiry concerning the Principles of Morals (1751); The Natural History of Religion (1757); a six-volume History of England from Roman times to 1688 (1754–62); a brief autobiography, My Own Life (1777); and Dialogues concerning Natural Religion (1778).
Hume’s neo-skeptical stance manifests itself in each of these works. He insists that philosophy “cannot go beyond experience; and any hypothesis, that pretends to discover the ultimate original qualities of human nature, ought at first to be rejected as presumptuous and chimerical.” He says of the Treatise that it “is very sceptical, and tends to give us a notion of the imperfections and narrow limits of the human understanding.” But he goes well beyond the conventional recognition of human limitations; from his skeptical starting place he projects an observationally based science of human nature, and produces a comprehensive and constructive account of human nature and experience.
Hume begins the Treatise with a discussion of the “elements” of his philosophy. Arguing that it is natural philosophers (scientists) who should explain how sensation works, he focuses on those entities that are the immediate and only objects present to the mind. These he calls “perceptions” and distinguishes into two kinds, “impressions” and “ideas.” Hume initially suggests that impressions (of which there are two kinds: of sensation and of reflection) are more forceful or vivacious than ideas, but some ideas (those of memory, e.g.) do sometimes take on enough force and vivacity to be called impressions, and belief also adds sufficient force and vivacity to ideas to make them practically indistinguishable from impressions. In the end we find that impressions are clearly distinguished from ideas only insofar as ideas are always causally dependent on impressions.
Thomas Reid charged that the allegedly representative theory of perception found in Descartes and Locke had served as a philosophical Trojan horse leading directly to skeptical despair. Hume was fully aware of the skeptical implications of this theory. He knew well those sections of Bayle and Locke that reveal the inadequacy of Descartes’s attempts to prove that there is an external world, and also appreciated the force of the objections brought by Bayle and Berkeley against the primary–secondary quality distinction championed by Locke. Hume adopted the view that the immediate objects of the mind are always “perceptions” because he thought it correct, and in spite of the fact that it leads to skepticism about the external world. Satisfied that the battle to establish absolutely reliable links between thought and reality had been fought and lost, Hume made no attempt to explain how our impressions of sensation are linked to their entirely “unknown causes.” He instead focused exclusively on perceptions qua objects of mind:
As to those impressions, which arise from the senses, their ultimate cause is, in my opinion, perfectly inexplicable by human reason, and ‘twill always be impossible to decide with certainty, whether they arise immediately from the object, or are produc’d by the creative power of the mind, or are deriv’d from the author of our being. Nor is such a question any way material to our present purpose. We may draw inferences from the coherence of our perceptions, whether they be true or Page 400 | Top of Articlefalse; whether they represent nature justly, or be mere illusions of the senses.
Book I of the Treatise is an effort to show how our perceptions cohere to form certain fundamental notions (those of space and time, causal connection, external and independent existence, and mind) in which, skeptical doubts notwithstanding, we repose belief and on which “life and action entirely depend.”
According to Hume, we have no direct impressions of space and time, and yet the ideas of space and time are essential to our existence. This he explains by tracing our idea of space to a “manner of appearance”: by means of two senses, sight and touch, we have impressions that array themselves as so many points on a contrasting background; the imagination transforms these particulars of experience into a “compound impression, which represents extension” or the abstract idea of space itself. Our idea of time is, mutatis mutandis, accounted for in the same way: “As ‘tis from the disposition of visible and tangible objects we receive the idea of space, so from the succession of ideas and impressions we form the idea of time.” The abstract idea of time, like all other abstract ideas, is represented in the imagination by a “particular individual idea of a determinate quantity and quality” joined to a term, ‘time’, that has general reference.
Hume is often credited with denying there is physical necessity and that we have any idea of necessary connection. This interpretation significantly distorts his intent. Hume was convinced by the Cartesians, and especially by Male-branche, that neither the senses nor reason can establish that one object (a cause) is connected together with another object (an effect) in such a way that the presence of the one entails the existence of the other. Experience reveals only that objects thought to be causally related are contiguous in time and space, that the cause is prior to the effect, and that similar objects have been constantly associated in this way. These are the defining, perceptible features of the causal relation. And yet there seems to be more to the matter. “There is,” he says, a “NECESSARY CONNECTION to be taken into consideration,” and our belief in that relation must be explained. Despite our demonstrated inability to see or prove that there are necessary causal connections, we continue to think and act as if we had knowledge of them. We act, for example, as though the future will necessarily resemble the past, and “wou’d appear ridiculous” if we were to say “that ‘tis only probable the sun will rise tomorrow, or that all men must dye.” To explain this phenomenon Hume asks us to imagine what life would have been like for Adam, suddenly brought to life in the midst of the world. Adam would have been unable to make even the simplest predictions about the future behavior of objects. He would not have been able to predict that one moving billiard ball, striking a second, would cause the second to move. And yet we, endowed with the same faculties, can not only make, but are unable to resist making, this and countless other such predictions.
What is the difference between ourselves and this putative Adam? Experience. We have experienced the constant conjunction (the invariant succession of paired objects or events) of particular causes and effects and, although our experience never includes even a glimpse of a causal connection, it does arouse in us an expectation that a particular event (a “cause”) will be followed by another event (an “effect”) previously and constantly associated with it. Regularities of experience give rise to these feelings, and thus determine the mind to transfer its attention from a present impression to the idea of an absent but associated object. The idea of necessary connection is copied from these feelings. The idea has its foundation in the mind and is projected onto the world, but there is nonetheless such an idea. That there is an objective physical necessity to which this idea corresponds is an untestable hypothesis, nor would demonstrating that such necessary connections had held in the past guarantee that they will hold in the future. Thus, while not denying that there may be physical necessity or that there is an idea of necessary connection, Hume remains a skeptic about causal necessity.
Hume’s account of our belief in future effects or absent causes – of the process of mind that enables us to plan effectively – is a part of this same explanation. Such belief involves an idea or conception of the entity believed in, but is clearly different from mere conception without belief. This difference cannot be explained by supposing that some further idea, an idea of belief itself, is present when we believe, but absent when we merely conceive. There is no such idea. Moreover, given the mind’s ability to freely join together any two consistent ideas, if such an idea were available we by an act of will could, contrary to experience, combine the idea of belief with any other idea, and by so doing cause ourselves to believe anything. Consequently, Hume concludes that belief can only be a “different MANNER of conceiving an object”; it is a livelier, Page 401 | Top of Articlefirmer, more vivid and intense conception. Belief in certain “matters of fact” – the belief that because some event or object is now being experienced, some other event or object not yet available to experience will in the future be experienced – is brought about by previous experience of the constant conjunction of two impressions. These two impressions have been associated together in such a way that the experience of one of them automatically gives rise to an idea of the other, and has the effect of transferring the force or liveliness of the impression to the associated idea, thereby causing this idea to be believed or to take on the lively character of an impression.
Our beliefs in continuing and independently existing objects and in our own continuing selves are, on Hume’s account, beliefs in “fictions,” or in entities entirely beyond all experience. We have impressions that we naturally but mistakenly suppose to be continuing, external objects, but analysis quickly reveals that these impressions are by their very nature fleeting and observer-dependent. Moreover, none of our impressions provides us with a distinctive mark or evidence of an external origin. Similarly, when we focus on our own minds, we experience only a sequence of impressions and ideas, and never encounter the mind or self in which these perceptions are supposed to inhere. To ourselves we appear to be merely “a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a perpetual flux and movement.” How do we, then, come to believe in external objects or our own selves and self-identity? Neither reason nor the senses, working with impressions and ideas, provide anything like compelling proof of the existence of continuing, external objects, or of a continuing, unified self. Indeed, these two faculties cannot so much as account for our belief in objects or selves. If we had only reason and the senses, the faculties championed by, respectively, the rationalists and empiricists, we would be mired in a debilitating and destructive uncertainty. So unfortunate an outcome is avoided only by the operation of an apparently unreliable third faculty, the imagination. It, by means of what appear to be a series of outright mistakes and trivial suggestions, leads us to believe in our own selves and in independently existing objects. The skepticism of the philosophers is in this way both confirmed (we can provide no arguments, e.g., proving the existence of the external world) and shown to be of little practical import. An irrational faculty, the imagination, saves us from the excesses of philosophy: “Philosophy wou’d render us entirely Pyrrhonian,” says Hume, were not nature, in the form of the imagination, too strong for it.
Books II and III of the Treatise and the Enquiry concerning the Principles of Morals reveal Hume’s concern to explain our moral behavior and judgments in a manner that is consistent with his science of human nature, but which nonetheless recognizes the irreducible moral content of these judgments. Thus he attempted to rescue the passions from the ad hoc explanations and negative assessments of his predecessors. From the time of Plato and the Stoics the passions had often been characterized as irrational and unnatural animal elements that, given their head, would under-mine humankind’s true, rational nature. Hume’s most famous remark on the subject of the passions, “Reason is, and ought only to be, the slave of the passions,” will be better understood if read in this context (and if it is remembered that he also claims that reason can and does extinguish some passions). In contrast to the long-standing orthodoxy, Hume assumes that the passions constitute an integral and legitimate part of human nature, a part that can be explained without recourse to physical or metaphysical speculation. The passions can be treated as of a piece with other perceptions: they are secondary impressions (“impressions of reflection”) that derive from prior impressions and ideas. Some passions (pride and humility, love and hatred) may be characterized as indirect; i.e., they arise as the result of a double relation of impressions and ideas that gives them one form of intentional character. These passions have both assignable causes (typically, the qualities of some person or some object belonging to a person) and a kind of indirect object (the person with the qualities or objects just mentioned); the object of pride or humility is always oneself, while the object of love or hatred is always another. The direct passions (desire, aversion, hope, fear, etc.) are feelings caused immediately by pleasure or pain, or the prospect thereof, and take entities or events as their intentional objects.
In his account of the will Hume claims that while all human actions are caused, they are nonetheless free. He argues that our ascriptions of causal connection have all the same foundation, namely, the observation of a “uniform and regular conjunction” of one object with another. Given that in the course of human affairs we observe “the same uniformity and regular operation of natural principles” found in the physical world, and that this uniformity results in an expectation of exactly the sort produced by physical Page 402 | Top of Articleregularities, it follows that there is no “negation of necessity and causes,” or no liberty of indifference. The will, that “internal impression we feel and are conscious of when we knowingly give rise to” any action or thought, is an effect always linked (by constant conjunction and the resulting feeling of expectation) to some prior cause. But, insofar as our actions are not forcibly constrained or hindered, we do remain free in another sense: we retain a liberty of spontaneity. Moreover, only freedom in this latter sense is consistent with morality. A liberty of indifference, the possibility of uncaused actions, would undercut moral assessment, for such assessments presuppose that actions are causally linked to motives.
Morality is for Hume an entirely human affair founded on human nature and the circumstances of human life (one form of naturalism). We as a species possess several notable dispositions that, over time, have given rise to morality. These include a disposition to form bonded family groups, a disposition (sympathy) to communicate and thus share feelings, a disposition – the moral sense – to feel approbation and disapprobation in response to the actions of others, and a disposition to form general rules. Our disposition to form family groups results in small social units in which a natural generosity operates. The fact that such generosity is possible shows that the egoists are mistaken, and provides a foundation for the distinction between virtue and vice. The fact that the moral sense responds differently to distinctive motivations – we feel approbation in response to well-intended actions, disapprobation in response to ill-intended ones – means that our moral assessments have an affective but nonetheless cognitive foundation. To claim that Nero was vicious is to make a judgment about Nero’s motives or character in consequence of an observation of him that has caused an impartial observer to feel a unique sentiment of disapprobation. That our moral judgments have this affective foundation accounts for the practical and motivational character of morality. Reason is “perfectly inert,” and hence our practical, action-guiding moral distinctions must derive from the sentiments or feelings provided by our moral sense.
Hume distinguishes, however, between the “natural virtues” (generosity, benevolence, e.g.) and the “artificial virtues” (justice, allegiance, e.g.). These differ in that the former not only produce good on each occasion of their practice, but are also on every occasion approved. In contrast, any particular instantiation of justice may be “contrary to the public good” and be approved only insofar as it is entailed by “a general scheme or system of action, which is advantageous.” The artificial virtues differ also in being the result of contrivance arising from “the circumstances and necessities of life.” In our original condition we did not need the artificial virtues because our natural dispositions and responses were adequate to maintain the order of small, kinshipbased units. But as human numbers increased, so too did the scarcity of some material goods lead to an increase in the possibility of conflict, particularly over property, between these units. As a consequence, and out of self-interest, our ancestors were gradually led to establish conventions governing property and its exchange. In the early stages of this necessary development our disposition to form general rules was an indispensable component; at later stages, sympathy enables many individuals to pursue the artificial virtues from a combination of self-interest and a concern for others, thus giving the fully developed artificial virtues a foundation in two kinds of motivation.
Hume’s Enquiry concerning Human Understanding and his Enquiry concerning the Principles of Morals represent his effort to “recast” important aspects of the Treatise into more accessible form. His Essays extend his human-centered philosophical analysis to political institutions, economics, and literary criticism. His best-selling History of England provides, among much else, an extended historical analysis of competing Whig and Tory claims about the origin and nature of the British constitution.
Hume’s trenchant critique of religion is found principally in his Enquiry concerning Human Understanding, Natural History of Religion, and Dialogues. In an effort to curb the excesses of religious dogmatism, Hume focuses his attention on miracles, on the argument from design, and on the origin of the idea of monotheism. Miracles are putative facts used to justify a commitment to certain creeds. Such commitments are often maintained with a mind-numbing tenacity and a disruptive intolerance toward contrary views. Hume argues that the widely held view of miracles as violations of a law of nature is incoherent, that the evidence for even the most likely miracle will always be counterbalanced by the evidence establishing the law of nature that the miracle allegedly violates, and that the evidence supporting any given miracle is necessarily suspect. His argument leaves open the possibility that violations of the laws of nature may have occurred, but shows that beliefs about such events lack the force of evidence needed to justify Page 403 | Top of Articlethe arrogance and intolerance that characterizes so many of the religious.
Hume’s critique of the argument from design has a similar effect. This argument purports to show that our well-ordered universe must be the effect of a supremely intelligent cause, that each aspect of this divine creation is well designed to fulfill some beneficial end, and that these effects show us that the Deity is caring and benevolent. Hume shows that these conclusions go well beyond the available evidence. The pleasant and well-designed features of the world are balanced by a good measure of the unpleasant and the plainly botched. Our knowledge of causal connections depends on the experience of constant conjunctions. Such connections cause the vivacity of a present impression to be transferred to the idea associated with it, and leave us believing in that idea. But in this case the effect to be explained, the universe, is unique, and its cause unknown. Consequently, we cannot possibly have experiential grounds for any kind of inference about this cause. On experiential grounds the most we can say is that there is a massive, mixed effect, and, as we have through experience come to believe that effects have causes commensurate to them, this effect probably does have a commensurately large and mixed cause. Furthermore, as the effect is remotely like the products of human manufacture, we can say “that the cause or causes of order in the universe probably bear some remote analogy to human intelligence.” There is indeed an inference to be drawn from the unique effect in question (the universe) to the cause of that effect, but it is not the “argument” of the theologians nor does it in any way support sectarian pretension or intolerance.
The Natural History of Religion focuses on the question of the origin of religion in human nature, and delivers a thoroughly naturalistic answer: the widespread but not universal belief in invisible and intelligent power can be traced to derivative and easily perverted principles of our nature. Primitive peoples found physical nature not an orderly whole produced by a beneficent designer, but arbitrary and fearsome, and they came to understand the activities of nature as the effect of petty powers that could, through propitiating worship, be influenced to ameliorate their lives. Subsequently, the same fears and perceptions transformed polytheism into monotheism, the view that a single, omnipotent being created and still controls the world and all that transpires in it. From this conclusion Hume goes on to argue that monotheism, apparently the more sophisticated position, is morally retrograde. Monotheism tends naturally toward zeal and intolerance, encourages debasing, “monkish virtues,” and proves itself a danger to society: it is a source of violence and a cause of immorality. In contrast, polytheism, which Hume here regards as a form of atheism, is tolerant of diversity and encourages genuine virtues that improve humankind. From a moral point of view, at least this one form of atheism is superior to theism.