H ume is our Politics, Hume is our Trade, Hume is our Philosophy, Hume is our Religion.” This statement by nineteenth century philosopher James Hutchison Stirling reflects the unique position in intellectual thought held by Scottish philosopher David Hume. Part of Hume’s fame and importance owes to his boldly skeptical approach to a range of philosophical subjects. In epistemology, he questioned common notions of personal identity, and argued that there is no permanent “self” that continues over time. He dismissed standard accounts of causality and argued that our conceptions of cause-effect relations are grounded in habits of thinking, rather than in the perception of causal forces in the external world itself. He defended the skeptical position that human reason is inherently contradictory, and it is only through naturally-instilled beliefs that we can navigate our way through common life. In the philosophy of religion, he argued that it is unreasonable to believe testimonies of alleged miraculous events, and he hints, accordingly, that we should reject religions that are founded on miracle testimonies. Against the common belief of the time that God’s existence could be proven through a design or causal argument, Hume offered compelling criticisms of standard theistic proofs. He also advanced theories on the origin of popular religious beliefs, grounding such notions in human psychology rather than in rational argument or divine revelation. The larger aim of his critique was to disentangle philosophy from religion and thus allow philosophy to pursue its own ends without rational over-extension or psychological corruption.
In moral theory, against the common view that God plays an important role in the creation and reinforcement of moral values, he offered one of the first purely secular moral theories, which grounded morality in the pleasing and useful consequences that result from our actions. He introduced the term “utility” into our moral vocabulary, and his theory is the immediate forerunner to the classic utilitarian views of Jeremy Bentham and John Stuart Mill. He is famous for the position that we cannot derive ought from is, the view that statements of moral obligation cannot simply be deduced from statements of fact. Some see Hume as an early proponent of the emotivist metaethical view that moral judgments principally express our feelings. He also made important contributions to aesthetic theory with his view that there is a uniform standard of taste within human nature, in political theory with his critique of social contractarianism, and economic theory with his anti-mercantilist views. As a philosophical historian, he defended the conservative view that British governments are best run through a strong monarchy.
David Hume was born in 1711 to a moderately wealthy family from Berwickshire Scotland, near Edinburgh. His background was politically Whiggish and religiously Calvinistic. As a child he faithfully attended the local Church of Scotland, pastored by his uncle. Hume was educated by his widowed mother until he left for the University of Edinburgh at the age of eleven. His letters describe how as a young student he took religion seriously and obediently followed a list of moral guidelines taken from The Whole Duty of Man, a popular Calvinistic devotional.
Leaving the University of Edinburgh around the age of fifteen to pursue his education privately, he was encouraged to consider a career in law, but his interests soon turned to philosophy. During these years of private study he began raising serious questions about religion, as he recounts in the following letter:
Tis not long ago that I burn’d an old Manuscript Book, wrote before I was twenty; which contain’d, Page after Page, the gradual Progress of my Thoughts on that head [i.e. religious belief]. It begun with an anxious Search after Arguments, to confirm the common Opinion: Doubts stole in, dissipated, return’d, were again dissipated, return’d again [To Gilbert Elliot of Minto, March 10, 1751].
Although his manuscript book was destroyed, several pages of his study notes survive from his early twenties. These show a preoccupation with proofs for God’s existence as well as atheism, particularly as he read on these topics in classical Greek and Latin texts and in Pierre Bayle’s skeptical Historical and Critical Dictionary. During these years of private study, some of which were in France, he composed his three-volume Treatise of Human Nature, which was published anonymously in two installments before he was thirty (1739, 1740). The Treatise explores several philosophical topics such as space, time, causality, external objects, the passions, free will, and morality, offering original and often skeptical appraisals of these notions. Book I of the Treatise was unfavorably reviewed in the History of the Works of the Learned with a succession of sarcastic comments. Although scholars today recognized it as a philosophical masterpiece, Hume was disappointed with the minimal interest his book spawned and said that “It fell dead-born from the press, without reaching such distinctions even to excite a murmur among the zealots” (My Own Life).
In 1741 and 1742 Hume published his two-volume Essays, Moral and Political, which were written in a popular style and were more successful than the Treatise. In 1744-1745 he was a candidate for the Chair of Moral Philosophy at the University of Edinburgh. The Edinburgh Town Council was responsible for electing a replacement, and critics opposed Hume by condemning his anti-religious writings. Chief among the critics was clergyman William Wishart (d. 1752), the Principal of the University of Edinburgh. Lists of allegedly dangerous propositions from Hume’s Treatise circulated, presumably penned by Wishart himself. In the face of such strong opposition, the Edinburgh Town Council consulted the Edinburgh ministers. Hoping to win over the clergy, Hume composed a point by point reply to the circulating lists of dangerous propositions, which was published as A Letter from a Gentleman to his Friend in Edinburgh. The clergy were not swayed, 12 of the 15 ministers voted against Hume, and he quickly withdrew his candidacy. In 1745 Hume accepted an invitation from General St Clair to attend him as secretary. He wore the uniform of an officer, and accompanied the general on an expedition against Canada (which ended in an incursion on the coast of France) and to an embassy post in the courts of Vienna and Turin.
Because of the success of his Essays, Hume was convinced that the poor reception of his Treatise was caused by its style rather than by its content. In 1748 he published his Enquiry Concerning Human Understanding, a more popular rendition of portions of Book I of the Treatise. The Enquiry also includes two sections not found in the Treatise: “Of Miracles” and a dialogue titled “Of a Particular Providence and of a Future State.” Each section contains direct attacks on religious belief. In 1751 he published his Enquiry Concerning the Principles of Morals, which recasts parts of Book III of the Treatise in a very different form. The work establishes a system of morality upon utility and human sentiments alone, and without appeal to divine moral commands. By the end of the century Hume was recognized as the founder of the moral theory of utility, and utilitarian political theorist Jeremy Bentham acknowledged Hume’s direct influence upon him. The same year Hume also published his Political Discourses, which drew immediate praise and influenced economic thinkers such as Adam Smith, William Godwin, and Thomas Malthus.
In 1751-1752 Hume sought a philosophy chair at the University of Glasgow, and was again unsuccessful. In 1752 his new employment as librarian of the Advocate’s Library in Edinburgh provided him with the resources to pursue his interest in history. There, he wrote much of his highly successful six-volume History of England (published from 1754 to 1762). The first volume was unfavorably received, partially for its defense of Charles I, and partially for two sections which attack Christianity. In one passage Hume notes that the first Protestant reformers were fanatical or “inflamed with the highest enthusiasm” in their opposition to Roman Catholic domination. In the second passage he labels Roman Catholicism a superstition which “like all other species of superstition. . . rouses the vain fears of unhappy mortals.” The most vocal attack against Hume’s History came from Daniel MacQueen in his 300 page Letters on Mr. Hume’s History. MacQueen scrutinizes the first volume of Hume’s work, exposing all the allegedly “loose and irreligious sneers” Hume makes against Christianity. Ultimately, this negative response led Hume to delete the two controversial passages from succeeding editions of the History.
Around this time Hume also wrote his two most substantial works on religion: The Dialogues Concerning Natural Religion and The Natural History of Religion. The Natural History appeared in 1757, but, on the advice of friends who wished to steer Hume away from religious controversy, the Dialogues remained unpublished until 1779, three years after his death. The Natural History aroused controversy even before it was made public. In 1756 a volume of Hume’s essays titled Five Dissertations was printed and ready for distribution. The essays included (1) “The Natural History of Religion;” (2) “Of the Passions;” (3) “Of Tragedy;” (4) “Of Suicide;” and (5) “Of the Immortality of the Soul.” The latter two essays made direct attacks on common religious doctrines by defending a person’s moral right to commit suicide and by criticizing the idea of life after death. Early copies were passed around, and Hume’s publisher was threatened with prosecution if the book was distributed as it was. The printed copies of Five Dissertations were then physically altered by removing the essays on suicide and immortality, and inserting a new essay “Of the Standard of Taste” in their place. Hume also took this opportunity to alter two particularly offending paragraphs in the Natural History. The essays were then bound with the new title Four Dissertations and distributed in January, 1757.
In the years following Four Dissertations, Hume completed his last major literary work, The History of England, which gave him a reputation as an historian that equaled, if not overshadowed, his reputation as a philosopher. In 1763, at age 50, he was invited to accompany the Earl of Hertford to the embassy in Paris, with a near prospect of being his secretary. He eventually accepted, and remarks at the reception he received in Paris “from men and women of all ranks and stations.” He returned to Edinburgh in 1766, and continued developing relations with the greatest minds of the time. Among these was Jean Jacques Rousseau who in 1766 was ordered out of Switzerland by the government in Berne. Hume offered Rousseau refuge in England and secured him a government pension. In England, Rousseau became suspicious of plots, and publicly charged Hume with conspiring to ruin his character, under the appearance of helping him. Hume published a pamphlet defending his actions and was exonerated. Another secretary appointment took him away from 1767-1768. Returning again to Edinburgh, his remaining years were spent revising and refining his published works, and socializing with friends in Edinburgh’s intellectual circles. In 1770, fellow Scotsman James Beattie published one of the harshest attacks on Hume’s philosophy to ever appear in print, entitled An Essay on the Nature and Immutability of Truth in Opposition to Sophistry and Scepticism. Hume was upset by Beattie’s relentless verbal attacks against him in the work, but the book made Beattie famous and King George III, who admired it, awarded Beattie a pension of £200 per year.
In 1776, at age sixty-five, Hume died from an internal disorder which had plagued him for many months. After his death, his name took on new significance as several of his previously unpublished works appeared. The first was a brief autobiography, My Own Life, but even this unpretentious work aroused controversy. As his friends, Adam Smith and S.J. Pratt, published affectionate eulogies describing how he died with no concern for an afterlife, religious critics responded by condemning this unjustifiable admiration of Hume’s infidelity. Two years later, in 1779, Hume’s Dialogues Concerning Natural Religion appeared. Again, the response was mixed. Admirers of Hume considered it a masterfully written work, while religious critics branded it as dangerous to religion. Finally, in 1782, Hume’s two suppressed essays on suicide and immortality were published. Their reception was almost unanimously negative.
Drawing heavily on John Locke’s empiricism, the opening sections of both the Treatise and Enquiry discuss the origins of mental perceptions as laid out in the following categorical scheme:
1. From memory
2. From imagination
a. From fancy
b. From understanding
(1) Involving relations of ideas
(2) Involving matters of fact
1. Of sensation (external)
2. Of reflection (internal)
Hume begins by dividing all mental perceptions between ideas (thoughts) and impressions (sensations and feelings), and then makes two central claims about the relation between them. First, advancing what is commonly called Hume’s copy thesis, he argues that all ideas are ultimately copied from impressions. That is, for any idea we select, we can trace the component parts of that idea to some external sensation or internal feeling. This claim places Hume squarely in the empiricist tradition, and he regularly uses this principle as a test for determining the content of an idea under consideration. As proof of the copy thesis, Hume challenges anyone who denies it “to shew a simple impression, that has not a correspondent idea, or a simple idea, that has not a correspondent impression” (Treatise, 1.1.1). Second, advancing what we may call Hume’s liveliness thesis, he argues that ideas and impressions differ only in terms of liveliness. For example, my impression of a tree is simply more vivid than my idea of that tree. One of his early critics, Lord Monboddo (1714–1799) pointed out an important implication of the liveliness thesis, which Hume himself presumably hides. Most modern philosophers held that ideas reside in our spiritual minds, whereas impressions originate in our physical bodies. So, when Hume blurs the distinction between ideas and impressions, he is ultimately denying the spiritual nature of ideas and instead grounding them in our physical nature. In short, all of our mental operations—including our most rational ideas—are physical in nature. As Monboddo writes, “One consequence, which Mr Hume has drawn from this doctrine, is, that, as our Mind can only operate by the organs of the Body, it must perish with the Body” (Ancient Metaphysics, 1782, 2.2.2).
Hume goes on to explain that there are several mental faculties that are responsible for producing our various ideas. He initially divides ideas between those produced by the memory, and those produced by the imagination. The memory is a faculty that conjures up ideas based on experiences as they happened. For example, the memory I have of my drive to the store is a comparatively accurate copy of my previous sense impressions of that experience. The imagination, by contrast, is a faculty that breaks apart and combines ideas, thus forming new ones. Hume uses the familiar example of a golden mountain: this idea is a combination of an idea of gold and an idea of a mountain. As our imagination takes our most basic ideas and leads us to form new ones, it is directed by three principles of association, namely, resemblance, contiguity, and cause and effect. By virtue of resemblance, an illustration or sketch, of a person leads me to an idea of that actual person. The idea of one apartment in a building leads me to think of the apartment contiguous to—or next to—the first. The thought of a scar on my hand leads me to think of a broken piece of glass that caused the scar.
As indicated in the above chart, our more complex ideas of the imagination are further divided between two categories. Some imaginative ideas represent flights of the fancy, such as the idea of a golden mountain; however, other imaginative ideas represent solid reasoning, such as predicting the trajectory of a thrown ball. The fanciful ideas are derived from the faculty of the fancy, and are the source of fantasies, superstitions, and bad philosophy. By contrast, sound ideas are derived from the faculty of the understanding—or reason—and are of two types: (1) involving relations of ideas; or (2) involving matters of fact. A relation of ideas (or relation between ideas) is a mathematical relation that is “discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe,” such as the mathematical statement “the square of the hypotenuse is equal to the square of the two sides” (Enquiry, 4). By contrast, a matter of fact, for Hume, is any object or circumstance which has physical existence, such as “the sun will rise tomorrow”. This split between relations of ideas and matters of fact is commonly called “Hume’s Fork”, and Hume himself uses it as a radical tool for distinguishing between well-founded ideas of the understanding, and unfounded ideas of the fancy. He dramatically makes this point at the conclusion of his Enquiry:
When we run over libraries, persuaded of these principles, what havoc must we make? If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: For it can contain nothing but sophistry and illusion (Enquiry, 12).
For Hume, when we imaginatively exercise our understanding regarding relations of ideas and matters of fact, our minds are guided by seven philosophical or “reasoning” relations, which are as follows:
Principles of reasoning concerning relations of ideas (involving demonstration): (1) resemblance; (2) contrariety; (3) degrees in quality; and (4) proportions in quantity or number
Principles of reasoning concerning matters of fact (involving judgments of probability): (5) identity; (6) relations in time and place; and (7) causation
Human understanding and reasoning at its best, then, involves ideas that are grounded in the above seven principles.
Much of Hume’s epistemology is driven by a consideration of philosophically important issues, such as space and time, cause-effect, external objects, personal identity, and free will. In his analysis of these issues in the Treatise, he repeatedly does three things. First, he skeptically argues that we are unable to gain complete knowledge of some important philosophical notion under consideration. Second, he shows how the understanding gives us a very limited idea of that notion. Third, he explains how some erroneous views of that notion are grounded in the fancy, and he accordingly recommends that we reject those erroneous ideas. We will follow this three-part scheme as we consider Hume’s discussions of various topics.
On the topic of space, Hume argues that our proper notions of space are confined to our visual and tactile experiences of the three-dimensional world, and we err if we think of space more abstractly and independently of those visual and tactile experiences. In essence, our proper notion of space is like what Locke calls a “secondary quality” of an object, which is spectator dependent, meaning grounded in the physiology of our perceptual mental processes. Thus, our proper notion of space is not like a “primary quality” that refers to some external state of affairs independent of our perceptual mental process. Following the above three-part scheme, (1) Hume skeptically argues that we have no ideas of infinitely divisible space (Treatise, 220.127.116.11). (2) When accounting for the idea we do have of space, he argues that “the idea of space is convey’d to the mind by two senses, the sight and touch; nor does any thing ever appear extended, that is not either visible or tangible” (Treatise, 18.104.22.168). Further, he argues that these objects—which are either visible or tangible—are composed of finite atoms or corpuscles, which are themselves “endow’d with colour and solidity.” These impressions are then “comprehended” or conceived by the imagination; it is from the structuring of these impressions that we obtain a limited idea of space. (3) In contrast to this idea of space, Hume argues that we frequently presume to have an idea of space that lacks visibility or solidity. He accounts for this erroneous notion in terms of a mistaken association that people naturally make between visual and tactile space (Treatise, 22.214.171.124).
Hume’s treatment of our idea of time is like his treatment of the idea of space, in that our proper idea of time is like a secondary quality, grounded in our mental operations, not a primary quality grounded in some external phenomenon beyond our experience. (1) He first maintains that we have no idea of infinitely divisible time (Treatise, 126.96.36.199). (2) He then notes Locke’s point that our minds operate at a range of speeds that are “fix’d by the original nature and constitution of the mind, and beyond which no influence of external objects on the senses is ever able to hasten or retard our thought” (Treatise, 188.8.131.52). The idea of time, then, is not a simple idea derived from a simple impression; instead, it is a copy of impressions as they are perceived by the mind at its fixed speed (Treatise, 184.108.40.206). (3) In contrast to this limited view of time, he argues that we frequently entertain a faulty notion of time that does not involve change or succession. The psychological account of this erroneous view is that we mistake time for the cause of succession instead of seeing it as the effect (Treatise, 220.127.116.11).
According to Hume, the notion of cause-effect is a complex idea that is made up of three more foundational ideas: priority in time, proximity in space, and necessary connection. Concerning priority in time, if I say that event A causes event B, one thing I mean is that A occurs prior to B. If B were to occur before A, then it would be absurd to say that A was the cause of B. Concerning the idea of proximity, if I say that A causes B, then I mean that B is in proximity to, or close to A. For example, if I throw a rock, and at that moment someone’s window in China breaks, I would not conclude that my rock broke a window on the other side of the world. The broken window and the rock must be in proximity with each other. Priority and proximity alone, however, do not make up our entire notion of causality. For example, if I sneeze and the lights go out, I would not conclude that my sneeze was the cause, even though the conditions of priority and proximity were fulfilled. We also believe that there is a necessary connection between cause A and effect B. During the modern period of philosophy, philosophers thought of necessary connection as a power or force connecting two events. When billiard ball A strikes billiard ball B, there is a power that the one event imparts to the other. In keeping with his empiricist copy thesis, that all ideas are copied from impressions, Hume tries to uncover the experiences which give rise to our notions of priority, proximity, and necessary connection. The first two are easy to explain. Priority traces back to our various experiences of time. Proximity traces back to our various experiences of space. But what is the experience which gives us the idea of necessary connection? This notion of necessary connection is the specific focus of Hume’s analysis of cause-effect.
Hume’s view is that our proper idea of necessary connection is like a secondary quality that is formed by the mind, and not, like a primary quality, a feature of the external world. (1) He skeptically argues that we cannot get an idea of necessary connection by observing it through sensory experiences (Treatise, 18.104.22.168 ff.). We have no external sensory impression of causal power when we observe cause-effect relationships; all that we ever see is cause A constantly conjoined with effect B. Neither does it arise from an internal impression, such as when we introspectively reflect on willed bodily motions or willing the creation of thoughts. These internal experiences are too elusive, and nothing in them can give content to our idea of necessary connection. (2) The idea we have of necessary connection arises as follows: we experience a constant conjunction of events A and B— repeated sense experiences where events resembling A are always followed by events resembling B. This produces a habit such that upon any further appearance of A, we expect B to follow. This, in turn, produces an internal feeling of expectation “to pass from an object to the idea of its usual attendant,” which is the impression from which the idea of necessary connection is copied (Treatise, 22.214.171.124). (3) A common but mistaken notion on this topic is that necessity resides within the objects themselves. He explains this mistaken belief by the natural tendency we have to impute subjectively perceived qualities to external things (Treatise, 126.96.36.199).
Hume’s view on external objects is that the mind is programmed to form some concept of the external world, although this concept or idea is really just a fabrication. (1) Hume’s skeptical claim here is that we have no valid conception of the existence of external things (Treatise, 188.8.131.52). (2) Nevertheless, he argues that we have an unavoidable “vulgar” or common belief in the continued existence of objects, and this idea he accounts for. His explanation is lengthy, but involves the following features. Perceptions of objects are disjointed and have no unity in and of themselves (Treatise, 184.108.40.206). In an effort to organize our perceptions, we first naturally assume that there is no distinction between our perceptions and the objects that are perceived (this is the so-called “vulgar” view of perception). We then conflate all ideas (of perceptions), which put our minds in similar dispositions (Treatise, 220.127.116.11); that is, we associate resembling ideas and attribute identity to their causes. Consequently, we naturally invent the continued and external existence of the objects (or perceptions) that produced these ideas (Treatise, 18.104.22.168). Lastly, we go on to believe in the existence of these objects because of the force of the resemblance between ideas (Treatise, 22.214.171.124). Although this belief is philosophically unjustified, Hume feels he has given an accurate account of how we inevitably arrive at the idea of external existence. (3) In contrast to the previous explanation of this idea, he recommends that we doubt a more sophisticated but erroneous notion of existence—the so-called philosophical view—which distinguishes between perceptions and the external objects that cause perceptions. The psychological motivation for accepting this view is this: our imagination tells us that resembling perceptions have a continued existence, yet our reflection tells us that they are interrupted. Appealing to both forces, we ascribe interruption to perceptions and continuance to objects (Treatise, 126.96.36.199).
Regarding the issue of personal identity, (1) Hume’s skeptical claim is that we have no experience of a simple, individual impression that we can call the self—where the “self” is the totality of a person’s conscious life. He writes, “For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe anything but the perception” (Treatise, 188.8.131.52). (2) Even though my perceptions are fleeting and I am a bundle of different perceptions, I nevertheless have some idea of personal identity, and that must be accounted for (Treatise, 184.108.40.206). Because of the associative principles, the resemblance or causal connection within the chain of my perceptions gives rise to an idea of myself, and memory extends this idea past my immediate perceptions (Treatise, 220.127.116.11 ff.). (3) A common abuse of the notion of personal identity occurs when the idea of a soul or unchanging substance is added to give us a stronger or more unified concept of the self (Treatise, 18.104.22.168).
On the issue of free will and determinism—or “liberty” and “necessity” in Hume’s terminology—Hume defends necessity. (1) He first argues that “all actions of the will have particular causes” (Treatise, 22.214.171.124), and so there is no such thing as an uncaused willful action. (2) He then defends the notion of a will that consistently responds to prior motivational causes: “our actions have a constant union with our motives, tempers, and circumstances” (Treatise, 126.96.36.199). These motives produce actions that have the same causal necessity observed in cause-effect relations that we see in external objects, such as when billiard ball A strikes and moves billiard ball B. In the same way, we regularly observe the rock-solid connection between motive A and action B, and we rely on that predictable connection in our normal lives. Suppose that a traveler, in recounting his observation of the odd behavior of natives in a distant country, told us that identical motives led to entirely different actions among these natives. We would not believe the traveler’s report. In business, politics, and military affairs, our leaders expect predicable behavior from us insofar as the same motives within us will always result in us performing the same action. A prisoner who is soon to be executed will assume that the motivations and actions of the prison guards and the executioner are so rigidly fixed that these people will mechanically carry out their duties and perform the execution, with no chance of a change of heart (Treatise, 188.8.131.52 ff.). (3) Lastly, Hume explains why people commonly believe in an uncaused will (Treatise, 184.108.40.206 ff.). One explanation is that people erroneously believe they have a feeling of liberty when performing actions. The reason is that, when we perform actions, we feel a kind of “looseness or indifference” in how they come about, and some people wrongly see this as “an intuitive proof of human liberty” (Treatise, 220.127.116.11).
In the Treatise Hume rejects the notion of liberty completely. While he gives no definition of “liberty” in that work, he argues that the notion is incompatible with necessity, and, at best, “liberty” simply means chance. In the Enquiry, however, he takes a more compatiblist approach. All human actions are caused by specific prior motives, but liberty and necessity are reconcilable when we define liberty as “a power of acting or not acting, according to the determinations of the will” (Enquiry, 8). Nothing in this definition of liberty is in conflict with the notion of necessity.
In all of the above discussions on epistemological topics, Hume performs a balancing act between making skeptical attacks (step 1) and offering positive theories based on natural beliefs (step 2). In the conclusion to Book 1, though, he appears to elevate his skepticism to a higher level and exposes the inherent contradictions in even his best philosophical theories. He notes three such contradictions. One centers on what we call induction. Our judgments based on past experience all contain elements of doubt; we are then impelled to make a judgment about that doubt, and since this judgment is also based on past experience it will in turn produce a new doubt. Once again, though, we are impelled to make a judgment about this second doubt, and the cycle continues. He concludes that “no finite object can subsist under a decrease repeated in infinitum.” A second contradiction involves a conflict between two theories of external perception, each of which our natural reasoning process leads us to. One is our natural inclination to believe that we are directly seeing objects as they really are, and the other is the more philosophical view that we only ever see mental images or copies of external objects. The third contradiction involves a conflict between causal reasoning and belief in the continued existence of matter. After listing these contradictions, Hume despairs over the failure of his metaphysical reasoning:
The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another [Treatise, 18.104.22.168].
He then pacifies his despair by recognizing that nature forces him to set aside his philosophical speculations and return to the normal activities of common life. He sees, though, that in time he will be drawn back into philosophical speculation in order to attack superstition and educate the world.
Hume’s emphasis on these conceptual contradictions is a unique aspect of his skepticism, and if any part of his philosophy can be designated “Humean skepticism” it is this. However, during the course of his writing the Treatise his view of the nature of these contradictions changed. At first he felt that these contradictions were restricted to theories about the external world, but theories about the mind itself would be free from them, as he explains here:
The essence and composition of external bodies are so obscure, that we must necessarily, in our reasonings, or rather conjectures concerning them, involve ourselves in contradictions and absurdities. But as the perceptions of the mind are perfectly known, and I have us'd all imaginable caution in forming conclusions concerning them, I have always hop'd to keep clear of those contradictions, which have attended every other system [Treatise, 22.214.171.124].
When composing the Appendix to the Treatise a year later, he changed his mind and felt that theories about the mind would also have contradictions:
I had entertained some hopes, that however deficient our theory of the intellectual world might be, it wou'd be free from those contradictions, and absurdities, which seem to attend every explication, that human reason can give of the material world. But upon a more strict review of the section concerning I find myself involv'd in such a labyrinth, that, I must confess, I neither know how to correct my former opinions, nor how to render them consistent. If this be not a good general reason for scepticism, 'tis at least a sufficient one (if I were not already abundantly supplied) for me to entertain a diffidence and modesty in all my decisions [Treatise, Appendix].
Thus, in the Treatise, the skeptical bottom line is that even our best theories about both physical and mental phenomena will be plagued with contradictions. In the concluding section of his Enquiry, Hume again addresses the topic of skepticism, but treats the matter somewhat differently: he rejects extreme skepticism but accepts skepticism in a more moderate form. He associates extreme Pyrrhonian skepticism with blanket attacks on all reasoning about the external world, abstract reasoning about space and time, or causal reasoning about matters of fact. He argues, though, that we must reject such skepticism since “no durable good can ever result from it.” Instead, he recommends a more moderate or Academic skepticism that tones down Pyrrhonism by, first, exercising caution and modesty in our judgments, and, second, by restricting our speculations to abstract reasoning and matters of fact.
Like many philosophers of his time, Hume developed a theory of the passions—that is, the emotions—categorizing them and explaining the psychological mechanisms by which they arise in the human mind. His most detailed account is in Book Two of the Treatise. Passions, according to Hume, fall under the category of impressions of reflection (as opposed to impressions of sensation). He opens his discussion with a taxonomy of types of passions, which are outlined here:
1. Calm (reflective pleasures and pains)
a. Direct (desire, aversion, joy, grief, hope, fear)
b. Indirect (love, hate, pride, humility)
He initially divides passions between the calm and the violent. He concedes that this distinction is imprecise, but he explains that people commonly distinguish between types of passions in terms of their degrees of forcefulness. Adding more precision to this common distinction, he maintains that calm passions are emotional feelings of pleasure and pain associated with moral and aesthetic judgments. For example, when I see a person commit a horrible deed, I will experience a feeling of pain. When I view a good work of art, I will experience a feeling of pleasure. In contrast to the calm passions, violent ones constitute the bulk of our emotions, and these divide between direct and indirect passions. For Hume, the key direct passions are desire, aversion, joy, grief, hope, and fear. They are called “direct” because they arise immediately—without complex reflection on our part—whenever we see something good or bad. For example, if I consider an unpleasant thing, such as being burglarized, then I will feel the passion of aversion. He suggests that sometimes these passions are sparked instinctively—for example, by my desire for food when I am hungry. Others, though, are not connected with instinct and are more the result of social conditioning. There is an interesting logic to the six direct passions, which Hume borrowed from a tradition that can be traced to ancient Greek Stoicism. We can diagram the relation between the six with this chart:
When good/bad objects are considered abstractly
Desire (towards good objects)
Aversion (towards evil objects)
When good/bad objects are actually present
Joy (towards good objects)
Grief (towards evil objects)
When good/bad objects are only anticipated
Hope (towards good objects)
Fear (towards evil objects)
Compare, for example, the passions that I will experience regarding winning the lottery vs. having my house burglarized. Suppose that I consider them purely in the abstract—or “consider’d simply” as Hume says (Treatise, 126.96.36.199). I will then desire to win the lottery and have an aversion towards being burglarized. Suppose that both situations are actually before me; I will then experience joy over winning the lottery and grief over being burglarized. Suppose, finally, that I know that at some unknown time in the future I will win the lottery and be burglarized. I will then experience hope regarding the lottery and fear of being burglarized.
Hume devotes most of Book 2 to an analysis of the indirect passions, his unique contribution to theories of the passions. The four principal passions are love, hate, pride, and humility. They are called “indirect” since they are the secondary effects of a previous feeling of pleasure and pain. Suppose, for example, that I paint a picture, which gives me a feeling of pleasure. Since I am the artist, I will then experience an additional feeling of pride. He explains in detail the psychological process that triggers indirect passions such as pride. Specifically, he argues that these passions arise from a double relation between ideas and impressions, which we can illustrate here with the passion of pride:
1. I have an initial idea of some possession, or “subject”, such as my painting, and this idea gives me pleasure.
2. Through the associative principle of resemblance, I then immediately associate this feeling of pleasure with a resembling feeling of pride (this association constitutes the first relation in the double relation).
3. This feeling of pride then causes me to have an idea of myself, as the “object” of pride.
4. Through some associative principle such as causality, I then associate the idea of myself with the idea of my painting, which is the “subject” of my pride (this association constitutes the second relation in the double relation).
According to Hume, the three other principal indirect passions arise in parallel ways. For example, if my painting is ugly and causes me pain, then I will experience the secondary passion of humility—perhaps more accurately expressed as “humiliation”. By contrast, if someone else paints a pleasing picture, then this will trigger in me a feeling of love for that artist—perhaps more accurately expressed as “esteem”. If the artist paints a painfully ugly picture, then this will trigger in me a feeling of “hatred” towards the artist—perhaps more accurately expressed as “disesteem”.
One of the most lasting contributions of Hume’s discussion of the passions is his argument that human actions must be prompted by passion, and never can be motivated by reason. Reason, he argues, is completely inert when it comes to motivating conduct, and without some emotion we would not engage in any action. Thus, he writes, “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” (Treatise, 188.8.131.52).
Like many of Hume’s philosophical views, his position on religious belief is also skeptical. Critics of religion during the eighteenth-century needed to express themselves cautiously to avoid being fined, imprisoned, or worse. Sometimes this involved placing controversial views in the mouth of a character in a dialogue. Other times it involved adopting the persona of a deist or fideist as a means of concealing a more extreme religious skepticism. Hume used all of the rhetorical devices at his disposal, and left it to his readers to decode his most controversial conclusions on religious subjects. During the Enlightenment, there were two pillars of traditional Christian belief: natural and revealed religion. Natural religion involves knowledge of God drawn from nature through the use of logic and reason, and typically involves logical proofs regarding the existence and nature of God, such as the causal and design arguments for God’s existence. Revealed religion involves knowledge of God contained in revelation, particularly the Bible, the quintessential examples of which are biblical prophesies and miracles where God intervenes in earthly affairs to confirm the Bible’s message of salvation. Hume attacks both natural and revealed religious beliefs in his various writings.
In a 1737 letter to Henry Home, Hume states that he intended to include a discussion of miracles in his Treatise, but ultimately left it out for fear of offending readers. His analysis of the subject eventually appeared some ten years later in his essay “Of Miracles” from the Enquiry, and is his first sustained attack on revealed religion. It is probably this main argument to which Hume refers. The first of this two-part essay contains the argument for which Hume is most famous: uniform experience of natural law outweighs the testimony of any alleged miracle. Let us imagine a scale with two balancing pans. In the first pan we place the strongest evidence in support of the occurrence of a miracle. In the second we place our life-long experience of consistent laws of nature. According to Hume, the second pan will always outweigh the first. He writes:
It is experience only, which gives authority to human testimony [regarding miracles]; and it is the same experience, which assures us of the laws of nature. When, therefore, these two kinds of experience are contrary, we have nothing to do but subtract the one from the other, and embrace an opinion, either on one side or the other, with that assurance which arises from the remainder. But according to the principle here explained, this subtraction, with regard to all popular religions, amounts to an entire annihilation [Enquiry, 10.1].
Regardless of how strong the testimony is in favor of a given miracle, it can never come close to counterbalancing the overwhelming experience of unvaried laws of nature. Thus, proportioning one’s belief to the evidence, the wise person must reject the weaker evidence concerning the alleged miracle.
In the second part of “Of Miracles”, Hume discusses four factors that count against the credibility of most miracle testimonies: (1) witnesses of miracles typically lack integrity; (2) we are naturally inclined to enjoy sensational stories, and this has us uncritically perpetuate miracle accounts; (3) miracle testimonies occur most often in less civilized countries; and (4) miracles support rival religious systems and thus discredit each other. But even if a miracle testimony is not encumbered by these four factors, we should still not believe it since it would be contrary to our consistent experience of laws of nature. He concludes his essay with the following cryptic comment about Christian belief in biblical miracles:
upon the whole, we may conclude, that the Christian Religion not only was at first attended with miracles, but even at this day cannot be believed by any reasonable person without one. Mere reason is insufficient to convince us of its veracity: And whoever is moved by Faith to assent to it, is conscious of a continued miracle in his own person, which subverts all the principles of his understanding, and gives him a determination to believe what is most contrary to custom and experience [Enquiry, 10.2].
At face value, his comment suggests a fideist approach to religious belief such as what Pascal recommends. That is, reason is incapable of establishing religious belief, and God must perform a miracle in our lives to make us open to belief through faith. However, according to the eighteenth-century Hume critic John Briggs, Hume’s real point is that belief in Christianity requires “miraculous stupidity” (The Nature of Religious Zeal, 1775).
Another attack on revealed religion appears in Hume’s essay “The Natural History of Religion” (1757). It is one of the first systematic attempts to explain the causes of religious belief solely in terms of psychological and sociological factors. We might see the “Natural History” as an answer to a challenge, such as the sort that William Adams poses here in his attack on Hume’s “Of Miracles”:
Whence could the religion and laws of this people [i.e., the Jews] so far exceed those of the wisest Heathens, and come out at once, in their first infancy, thus perfect and entire; when all human systems are found to grow up by degrees, and to ripen, after many improvements; into perfection [An Essay, Part 2]?
According to Adams, only divine intervention can account for the sophistication of the ancient Jewish religion. In the “Natural History,” though, Hume offers an alternative explanation, and one that is grounded solely in human nature, without God’s direct involvement in human history.
The work may be divided into three parts. In the first (Sections 1 and 4), Hume argues that polytheism, and not monotheism, was the original religion of primitive humans. Monotheism, he believes, was only a later development that emerged with the progress of various societies. The standard theory in Judeo-Christian theology was that early humans first believed in a single God, but as religious corruption crept in, people lapsed into polytheism. Hume was the first writer to systematically defend the position of original polytheism. In the second part (Sections 2-3, 5-8), Hume establishes the psychological principles that give rise to popular religious belief. His thesis is that natural instincts—such as fear and the propensity to adulate—are the true causes of popular religious belief, and not divine intervention or rational argument. The third part of this work (Sections 9-15) compares various aspects of polytheism with monotheism, showing that one is no more superior than the other. Both contain points of absurdity. From this he concludes that we should suspend belief on the entire subject of religious truth.
Around the same time that Hume was composing his “Natural History of Religion” he was also working on his Dialogues Concerning Natural Religion, which appeared in print two decades later, after his death. As the title of the work implies, it is a critique of natural religion, in contrast with revealed religion. There are three principal characters in the Dialogues. A character named Cleanthes, who espouses religious empiricism, defends the design argument for God’s existence, but rejects the causal argument. Next, a character named Demea, who is a religious rationalist, defends the causal argument for God’s existence, but rejects the design argument. Finally, a character named Philo, who is a religious skeptic, argues against both the design and causal arguments. The main assaults on theistic proofs are conveyed by both Cleanthes and Philo, and, to that extent, both of their critiques likely represent Hume’s views.
The specific version of the causal argument that Hume examines is one by Samuel Clarke (and Leibniz before him). Simplistic versions of the causal argument maintain that when we trace back the causes of things in the universe, the chain of causes cannot go back in time to infinity past; there must be a first cause to the causal sequence, which is God. Clarke’s version differs in that it is theoretically possible for causal sequences of events to trace back through time to infinity past. Thus, we cannot argue that God’s existence is required to initiate a sequence of temporal causes. Nevertheless, Clarke argued, an important fact still needs to be explained: the fact that this infinite temporal sequence of causal events exists at all. Why does something exist rather than nothing? God, then, is the necessary cause of the whole series. In response, the character Cleanthes argues that the flaw in the cosmological argument consists in assuming that there is some larger fact about the universe that needs explaining beyond the particular items in the series itself. Once we have a sufficient explanation for each particular fact in the infinite sequence of events, it makes no sense to inquire about the origin of the collection of these facts. That is, once we adequately account for each individual fact, this constitutes a sufficient explanation of the whole collection. He writes, “Did I show you the particular causes of each individual in a collection of twenty particles of matter, I should think it very unreasonable, should you afterwards ask me, what was the cause of the whole twenty” (Dialogues, 9).
The design argument for God’s existence is that the appearance of design in the natural world is evidence for the existence of a divine designer. The specific version of the argument that Hume examines is one from analogy, as stated here by Cleanthes:
The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the productions of human contrivance; of human designs, thought, wisdom, and intelligence. Since, therefore, the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man (Dialogues, 2).
Philo presents several criticisms against the design argument, many of which are now standard in discussions of the issue. According to Philo, the design argument is based on a faulty analogy: we do not know whether the order in nature was the result of design, since, unlike our experience with the creation of machines, we did not witness the formation of the world. In Philo’s words, “will any man tell me with a serious countenance, that an orderly universe must arise from some thought and art like the human, because we have experience of it? To ascertain this reasoning, it were requisite that we had experience of the origin of worlds; and it is not sufficient, surely, that we have seen ships and cities arise from human art and contrivance” (ibid). Further, the vastness of the universe also weakens any comparison with human artifacts. Although the universe is orderly here, it may be chaotic elsewhere. Similarly, if intelligent design is exhibited only in a small fraction of the universe, then we cannot say that it is the productive force of the whole universe. Philo states that “A very small part of this great system, during a very short time, is very imperfectly discovered to us; and do we thence pronounce decisively concerning the origin of the whole?” (ibid). Philo also argues that natural design may be accounted for by nature alone, insofar as matter may contain within itself a principle of order, and “This at once solves all difficulties” (Dialogues, 6). And even if the design of the universe is of divine origin, we are not justified in concluding that this divine cause is a single, all powerful, or all good being. According to Philo, “Whether all these attributes are united in one subject, or dispersed among several independent beings, by what phenomena in nature can we pretend to decide the controversy?” (Dialogues 5).
Hume’s moral theory appears in Book 3 of the Treatise and in An Enquiry Concerning the Principles of Morals (1751). He opens his discussion in the Treatise by telling us what moral approval is not: it is not a rational judgment about either conceptual relations or empirical facts. To make his case he criticizes Samuel Clarke’s rationalistic account of morality, which is that we rationally judge the fitness or unfitness of our actions in reference to eternal laws of righteousness, that are self-evidently known to all humans, just as is our knowledge of mathematical relations. Hume presents several arguments against Clarke’s view, one of which is an analogy from arboreal parricide: a young tree that overgrows and kills its parent exhibits the same alleged relations as a human child killing his parent. “Is not the one tree the cause of the other’s existence; and the latter the cause of the destruction of the former, in the same manner as when a child murders his parent?” (Treatise, 184.108.40.206). If morality is a question of relations, then the young tree is immoral, which is absurd. Hume also argues that moral assessments are not judgments about empirical facts. Take any immoral action, such as willful murder: “examine it in all lights, and see if you can find that matter of fact, or real existence, which you call vice” (Treatise, 220.127.116.11). You will not find any such fact, but only your own feelings of disapproval. In this context Hume makes his point that we cannot derive statements of obligation from statements of fact. When surveying various moral theories, Hume writes, “I am surpriz’d to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought or an ought not” (Treatise, 18.104.22.168). This move from is to ought is illegitimate, he argues, and is why people erroneously believe that morality is grounded in rational judgments.
Thus far Hume has only told us what moral approval is not, namely a judgment of reason. So what then does moral approval consist of? It is an emotional response, not a rational one. The details of this part of his theory rest on a distinction between three psychologically distinct players: the moral agent, the receiver, and the moral spectator. The moral agent is the person who performs an action, such as stealing a car; the receiver is the person impacted by the conduct, such as the owner of the stolen car; and the moral spectator is the person who observes and, in this case, disapproves of the agent’s action. This agent-receiver-spectator distinction is the product of earlier moral sense theories championed by the Earl of Shaftesbury (1671-1713), Joseph Butler (1692-1752), and Francis Hutcheson (1694-1747). Most generally, moral sense theories maintained that humans have a faculty of moral perception, similar to our faculties of sensory perception. Just as our external senses detect qualities in external objects, such as colors and shapes, so too does our moral faculty detect good and bad moral qualities in people and actions.
For Hume, all actions of a moral agent are motivated by character traits, specifically either virtuous or vicious character traits. For example, if you donate money to a charity, then your action is motivated by a virtuous character trait. Hume argues that some virtuous character traits are instinctive or natural, such as benevolence, and others are acquired or artificial, such as justice. As an agent, your action will have an effect on a receiver. For example, if you as the agent give food to a starving person, then the receiver will experience an immediately agreeable feeling from your act. Also, the receiver may see the usefulness of your food donation, insofar as eating food will improve his health. When considering the usefulness of your food donation, then, the receiver will receive another agreeable feeling from your act. Finally, I, as a spectator, observe these agreeable feelings that the receiver experiences. I, then, will sympathetically experience agreeable feelings along with the receiver. These sympathetic feelings of pleasure constitute my moral approval of the original act of charity that you, the agent, perform. By sympathetically experiencing this pleasure, I thereby pronounce your motivating character trait to be a virtue, as opposed to a vice. Suppose, on the other hand, that you as an agent did something to hurt the receiver, such as steal his car. I as the spectator would then sympathetically experience the receiver’s pain and thereby pronounce your motivating character trait to be a vice, as opposed to a virtue.
In short, that is Hume’s overall theory. There are, though, some important details that should also be mentioned. First, it is tricky to determine whether an agent’s motivating character trait is natural or artificial, and Hume decides this one virtue at a time. For Hume, the natural virtues include benevolence, meekness, charity, and generosity. By contrast, the artificial virtues include justice, keeping promises, allegiance and chastity. Contrary to what one might expect, Hume classifies the key virtues that are necessary for a well-ordered state as artificial, and he classifies only the more supererogatory virtues as natural. Hume’s critics were quick to point out this paradox. Second, to spark a feeling of moral approval, the spectator does not have to actually witness the effect of an agent’s action upon a receiver. The spectator might simply hear about it, or the spectator might even simply invent an entire scenario and think about the possible effects of hypothetical actions. This happens when we have moral reactions when reading works of fiction: “a very play or romance may afford us instances of this pleasure, which virtue conveys to us; and pain, which arises from vices” (Treatise, 22.214.171.124).
Third, although the agent, receiver, and spectator have psychologically distinct roles, in some situations a single person may perform more than one of these roles. For example, if I as an agent donate to charity, as a spectator to my own action I can also sympathize with the effect of my donation on the receiver. Finally, given various combinations of spectators and receivers, Hume concludes that there are four irreducible categories of qualities that exhaustively constitute moral virtue: (1) qualities useful to others, which include benevolence, meekness, charity, justice, fidelity and veracity; (2) qualities useful to oneself, which include industry, perseverance, and patience; (3) qualities immediately agreeable to others, which include wit, eloquence and cleanliness; and (4) qualities immediately agreeable to oneself, which include good humor, self-esteem and pride. For Hume, most morally significant qualities and actions seem to fall into more than one of these categories. When Hume spoke about an agent’s “useful” consequences, he often used the word “utility” as a synonym. This is particularly so in the Enquiry Concerning the Principles of Morals where the term “utility” appears over 50 times. Moral theorists after Hume thus depicted his moral theory as the “theory of utility”—namely, that morality involves assessing the pleasing and painful consequences of actions on the receiver. It is this concept and terminology that inspired classic utilitarian philosophers, such as Jeremy Bentham (1748–1832).
Hume wrote two influential essays on the subject of aesthetic theory. In “Of Tragedy” (1757) he discusses the psychological reasons why we enjoy observing depictions of tragic events in theatrical production. He argues that “the energy of expression, the power of numbers, and the charm of imitation” convey the sense of pleasure. He particularly stresses the technical artistry involved when an artistic work imitates the original. In “Of the Standard of Taste” (1757) he argues that there is a uniform sense of artistic judgment in human nature, similar to our uniform sense of moral judgment. Specific objects consistently trigger feelings of beauty within us, as our human nature dictates. Just as we can refine our external senses such as our palate, we can also refine our sense of artistic beauty and thus cultivate a delicacy of taste. In spite of this uniform standard of taste, two factors create some difference in our judgments: “the one is the different humours of particular men; the other, the particular manners and opinions of our age and country.”
In political theory, Hume has both theoretical discussions on the origins of government and more informal essays on popular political controversies of his day. In his theoretical discussions, he attacks two basic notions in eighteenth-century political philosophy: the social contract and the instinctive nature of justice regarding private property. In his 1748 essay “Of the Original Contract,” he argues that political allegiance is not grounded in any social contract, but instead on our general observation that society cannot be maintained without a governmental system. He concedes that in savage times there may have been an unwritten contract among tribe members for the sake of peace and order. However, he argues, this was no permanent basis of government as social contract theorists pretend. There is nothing to transmit that original contract onwards from generation to generation, and our experience of actual political events shows that governmental authority is founded on conquest, not elections or consent. We do not even tacitly consent to a contract since many of us have no real choice about remaining in our countries: “Can we seriously say that a poor peasant or artisan has a free choice to leave his country, when he knows no foreign language or manners, and lives from day to day by the small wages which he acquires?” Political allegiance, he concludes, is ultimately based on a primary instinct of selfishness, and only through reflection will we see how we benefit from an orderly society.
Concerning private property, in both the Treatise and the Enquiry Concerning the Principles of Morals (1751), Hume in essence argues against Locke’s notion of the natural right to private property. For Hume, we have no primary instinct to recognize private property, and all conceptions of justice regarding property are founded solely on how useful the convention of property is to us. We can see how property ownership is tied to usefulness when considering scenarios concerning the availability of necessities. When necessities are in overabundance, I can take what I want any time, and there is no usefulness in my claiming any property as my own. When the opposite happens and necessities are scarce, I do not acknowledge anyone’s claim to property and take what I want from others for my own survival. Thus, “the rules of equity or justice [regarding property] depend entirely on the particular state and condition in which men are placed, and owe their origin and existence to that utility, which results to the public from their strict and regular observance” (Enquiry Concerning the Principles of Morals, 3). Further, if we closely inspect human nature, we will never find a primary instinct that inclines us to acknowledge private property. It is nothing like the primary instinct of nest building in birds. While the sense of justice regarding private property is a firmly fixed habit, it is nevertheless its usefulness to society that gives it value.
As for Hume’s informal essays on popular political controversies, several of these involve party disputes between the politically conservative Tory party that supported a strong monarchy, and the politically liberal Whig party which supported a constitutional government. Two consistent themes emerge in these essays. First, in securing peace, a monarchy with strong authority is probably better than a pure republic. Hume sides with the Tories because of their traditional support of the monarchy. Except in extreme cases, he opposes the Lockean argument offered by Whigs that justifies overthrowing political authorities when those authorities fail to protect the rights of the people. Hume notes, though, that monarchies and republics each have their strong points. Monarchies encourage the arts, and republics encourage science and trade. Hume also appreciates the mixed form of government within Great Britain, which fosters liberty of the press. The second theme in Hume’s political essays is that revolutions and civil wars principally arise from zealousness within party factions. Political moderation, he argues, is the best antidote to potentially ruinous party conflict.
In economic theory, Hume wrote influential essays on money, interest, trade, credit, and taxes. Many of these target the mercantile system and its view that a country increases its wealth by increasing the quantity of gold and silver in that country. For mercantilists, three means were commonly employed to this end: (1) capture gold, silver and raw material from other countries through colonization; (2) discourage imports through tariffs and monopolies, which keeps acquired gold and silver within one’s country’s borders; and, (3) increase exports, which brings in money from outside countries. In Great Britain, mercantile policies were instituted through the Navigation Acts, which prohibited trade between British colonies and foreign countries. These protectionist laws ultimately led to the American Revolution. The most famous of Hume’s anti-mercantilist arguments is now called Hume’s gold-flow theory, and appears in his essays “Of Money” (1752) and “Of the Balance of Trade” (1752). Contrary to mercantilists who advocated locking up money in one’s home country, Hume argued that increased money in one country automatically disperses to other countries. Suppose, for example, that Great Britain receives an influx of new money. This new money will drive up prices of labor and domestic products in Great Britain. Products in foreign countries, then, will be cheaper than in Great Britain; Britain, then, will import these products, thereby sending new money to foreign countries. Hume compares this reshuffling of wealth to the level of fluids in interconnected chambers: if I add fluid to one chamber, then, under the weight of gravity, this will disperse to the others until the level is the same in all chambers. A similar phenomenon will occur if we lose money in our home country by purchasing imports from foreign countries. As the quantity of money decreases in our home country, this will drive down the prices of labor and domestic products. Our products, then, will be cheaper than foreign products, and we will gain money through exports. On the fluid analogy, by removing fluid from one chamber, more fluid is drawn in from surrounding chambers.
Although Hume is now remembered mainly as a philosopher, in his own day he had at least as much impact as a historian. His History of England appeared in four installments between 1754 and 1762 and covers the periods of British history from most ancient times through the seventeenth-century. To his 18th and 19th century readers, he was not just another historian, but a uniquely philosophical historian who had an ability to look into the minds of historical figures and uncover the motives behind their conduct. A political theme underlying the whole History is, once again, a conflict between Tory and Whig ideology. In the Britain of Hume’s day, a major point of contention between the two parties was whether the English government was historically an absolute or limited monarchy. Tories believed that it was traditionally absolute, with governmental authority being grounded in royal prerogative. Whigs, on the other hand, believed that it was traditionally limited, with the foundation of government resting in the individual liberty of the people, as expressed in the parliamentary voice of the commons. As a historian, Hume felt that he was politically moderate, tending to see both the strengths and weaknesses in opposing viewpoints:
With regard to politics and the character of princes and great men, I think I am very moderate. My views of things are more conformable to Whig principles; my representations of persons to Tory prejudices. Nothing can so much prove that men commonly regard more persons than things, as to find that I am commonly numbered among the Tories [Hume to John Clephane, 1756].
However, to radical Whig British readers, Hume was a conservative Tory who defended royal prerogative.
Hume takes two distinct positions on the prerogative issue. From a theoretical and idealistic perspective, he favored a mixed constitution, mediating between the authority of the monarch and that of the Parliament. Discussing this issue in his 1741 Essays, he holds that we should learn “the lesson of moderation in all our political controversies.” However, from the perspective of how British history actually unfolded, he emphasized royal prerogative. And, as a “philosophical historian,” he tried to show how human nature gave rise to the tendency towards royal prerogative. In his brief autobiography, “My Own Life,” he says that he rejected the “senseless clamour” of Whig ideology, and believed “It is ridiculous to consider the English constitution before that period [of the Stuart Monarchs] as a regular plan of liberty.” Gilbert Stuart best encapsulated Hume’s historical stance on the prerogative issue: “his history, from its beginning to its conclusion, is chiefly to be regarded as a plausible defence of prerogative” (A View of Society in Europe, 1778, 2.1.1). In short, Hume’s Tory narrative is this. As early as the Anglo Saxon period, the commons did not participate in the king’s advisory council. The Witenagemot, for example, was only a council of nobles and bishops, which the king could listen to or ignore as he saw fit. Throughout the succeeding centuries, England’s great kings were those who exercised absolute rule, and took advantage of prerogative courts such as the Star Chamber. Elizabeth—England’s most beloved monarch—was in fact a tyrant, and her reign was much like that of a Turkish sultan. Charles I—a largely virtuous man—tried to follow in her footsteps as a strong monarch. After a few minor lapses in judgment, and a few too many concessions to Catholics, Protestant zealots rose up against him, and he was ultimately executed. To avoid over-characterizing royal prerogative, Hume occasionally condemns arbitrary actions of monarchs and praises efforts for preserving liberty. Nevertheless, Whig critics like Gilbert Stuart argued that Hume’s emphasis was decisively in favor of prerogative.
There is an irony to Hume’s preference for prerogative over civil liberty. His philosophical writings were among the most controversial pieces of literature of the time, and would have been impossible to publish if Britain was not a friend to liberty. Although Hume was certainly no enemy to liberty, he believed that it was best achieved through moderation rather than Whig radicalism. He writes, “If any other rule than established practice be followed, factions and dissentions must multiply without end” (History, Appendix 3). To Hume’s way of thinking, the loudest voices favoring liberty were Calvinistic religious fanatics who accomplished little more than dissention. A strong, centralized and moderating force was the best way to avoid factious disruption from the start.
There are many published editions of Hume’s writings, the best of which are as follows (listed chronologically).
The secondary literature on Hume is voluminous. Below are a few works that cover all aspects of Hume’s philosophy. For works on specific aspects of Hume, such as his epistemology, see other IEP articles on Hume.