David Hume

A Scottish philosopher who developed the philosophy of mitigated skepticism, which remains a viable alternative to the systems of rationalism, empiricism, and idealism.

If one was to judge a philosopher by a gauge of relevance—the quantity of issues and arguments raised by him that remain central to contemporary thought—David Hume would be rated among the most important figures in philosophy. Ironically, his philosophical writings went unnoticed during his lifetime, and the considerable fame he achieved derived from his work as an essayist and historian.

With respect to Hume's life there is no better source than his succinct autobiography, My Own Life, written four months before his death. He was born on April 26, 1711, on the family estate, Ninewells, near Edinburgh, Scotland. According to Hume, the “ruling passion” of his life was literature, and his story contains “little more than the History of my writings.” As a second son, he was not entitled to a large inheritance, and he failed in two family-sponsored careers, law and business, because of his “unsurmountable aversion to everything but the pursuits of Philosophy and general learning.” Until he was past 40, Hume was employed only twice. He spent a year in England as a tutor to a mentally ill nobleman, and from 1745–47 Hume was an officer and aide-decamp to Gen. James Sinclair and attended him on an expedition to the coast of France and military embassies in Vienna and Turin.

Major works

During an earlier stay in France (1734–37) Hume had written his major philosophic work, A Treatise of Human Nature. The first two volumes were published in 1739 and the third appeared in 1740. The critical reception of the work was unfortunate. In Hume's own words, the Treatise “fell dead born from the press.” Book I of the Treatise was recast as An Enquiry concerning Human Understanding and published in 1748. The third volume with minor revisions appeared in 1751 as An Enquiry concerning the Principles of Morals. The second volume of the Treatise was republished as Part 2 of Four Dissertations in 1757. Two sections of this work dealing with liberty and necessity had been incorporated in the first Enquiry. Hume's other important work, Dialogues concerning Natural Religion, was substantially complete by the mid-1750s, but because of its controversial nature it was not published until after his death.

During his lifetime, Hume's reputation derived from the publication of his Political Discourses (1751) and six-volume History of England (1754–1762). When he went to France in 1763 as secretary to the English ambassador, Hume discovered that he was a literary celebrity and a revered figure among the philosophes. He led a very happy and active social life even after his retirement to Edinburgh in 1769. He died there on August 25, 1776. He specified in his will that the gravestone be marked only with his name and dates, “leaving it to Posterity to add the rest.”

Mitigated skepticism

Hume was aware, however, that this sort of skepticism with regard to the senses does violence to common sense. He suggests that a position of complete skepticism is neither serious nor useful. Academic skepticism (the name derives from a late branch of Plato's school) states that one can never know the truth or falsity of any statement (except, of course, this one). It is, however, a self-refuting theory and is confounded by life itself because people make inferences on the basis of their impressions whether they be true or false, real or imaginary. Total skepticism as a position is not practical since nature is always too strong for principle. Hume, therefore, advanced what he called mitigated skepticism. In addition to the exercise of caution in reasoning, this approach attempts to limit philosophical inquiries to topics that are adapted to the capacities of human intelligence. It excludes all metaphysical questions concerning the origin of either mind or object as being incapable of demonstration.

Theory of knowledge

Even though an ultimate explanation of both the subject or object of knowledge is impossible, Hume provides a description of how man senses and understands. He emphasizes the utility of knowledge as opposed to its correctness and suggests that experience begins with feeling rather than thought. He uses the term perception in its traditional sense—that is, whatever can be present to the mind from the senses, passions, thought, or reflection. Nonetheless, he distinguishes between impressions that are felt and ideas that are thought. In this he stresses the difference between feeling a toothache and thinking about such a pain. Both impressions and ideas are subdivided further into simple and complex. For example, the idea of heat is simple whereas the idea of combustion is complex.

Theory of ideas

Hume accepts the Cartesian doctrine of the distinct idea—conceivability subject only to the principle of contradiction—as both the unit of reasoning and the criterion of truth. For Hume, since truth is posterior to fact, the ideas of reason only express what the mind thinks about reality. Distinct ideas, or imaginative concepts, are pure antinomies apart from experience as every factual proposition is equally valid a priori. Hume does acknowledge that such propositions are not equally meaningful either to thought or action. On the level of ideas, Hume offers a conceptual correlative to the exemption of sensation as a form of cognition by his recognition that the meaning of ideas is more important than their truth. What separates meaningful propositions from mere concepts is the subjective impression of belief.

Belief, or the vivacity with which the mind conceives certain ideas and associations, results from the reciprocal relationship between experience and imagination. The cumulative experience of the past and present—for example, the relational factors of constancy, conjunction, and resemblance—gives a bias to the imagination. But it is man's imaginative anticipations of the future that give meaning to his experience. Neither the relational elements of experience nor the propensive function of the imagination, from the viewpoint of the criterion of truth, possesses the slightest rational justification. Hence, the interplay between the criterion of truth and the logic of the imagination explains both Hume's skepticism and his conception of sensation and intellection.

The most celebrated example of this argument is Hume's analysis of the causal relation. Every statement that points beyond what is immediately available to the senses and memory rests on an assumption and/or extension of the cause and effect relation. For example, in these two cases: I see lightning and hear thunder; I see a rabbit and then a fox. The question is why I am right in concluding that lightning causes thunder but wrong in believing that rabbits cause foxes. Experience, in both instances, reveals an A that is followed by B, and repeated experiences show that A is always followed by B. While the constant conjunction of A and B might eliminate the rabbit-fox hypothesis, it is of no help in explaining causality because there are all sorts of objects, such as tables and chairs, which are similarly conjoined but not supposed to be causally related. Therefore, experience reveals only that constant conjunction and priority are sufficient but not necessary conditions for establishing a causal connection. And it is necessity, understood as that which cannot be otherwise than it is, which makes a relation causal in the propositional form of “If A then B must appear and if no A then no B.”



Ayer, Alfred. Hume: A Very Short Introduction. New York: Oxford University Press, 2000.

Burton, John H. Life and Correspondence of David Hume. 1846 Reprint. New York: Garland, 1983.

Harris, James A. Hume: An Intellectual Biography. New York: Cambridge University Press, 2015.


“Hume Texts.” davidhume.org http://www.davidhume.org (accessed August 16, 2015).