David Hume

David Hume (born David Home; 7 May 1711 – 25 August 1776) was a Scottish philosopher, historian, economist and essayist who is known for his highly influential system of empiricism, philosophical scepticism and metaphysical naturalism. Beginning with A Treatise of Human Nature (1739–40), Hume strove to create a naturalistic science of man that examined the psychological basis of human nature. Following John Locke, Hume rejected the existence of innate ideas, holding that all our ideas derive ultimately from impressions, but in his fork he distinguished relations of ideas, known a priori, from matters of fact, whose knowledge rests on experience. This places him in the empiricist tradition of Locke and George Berkeley, while drawing his experimental method from Francis Bacon.

Hume argued that inductive reasoning and belief in causality cannot be justified empirically; instead, they result from custom and mental habit. People never actually perceive that one event causes another but experience only the "constant conjunction" of events. This problem of induction means that to draw any causal inferences from past experience, it is necessary to presuppose that the future will resemble the past; this metaphysical presupposition cannot itself be grounded in prior experience.

An opponent of philosophical rationalists, Hume held that passions rather than reason govern human behaviour, proclaiming that "Reason is, and ought only to be the slave of the passions." Hume was also a sentimentalist who held that ethics are based on emotion or sentiment rather than abstract moral principle. He maintained an early commitment to naturalistic explanations of moral phenomena and is usually accepted by historians of European philosophy to have first clearly expounded the is–ought problem, or the idea that a statement of fact alone can never give rise to a normative conclusion of what ought to be done.

Hume denied that people have an actual conception of the self, positing that they experience only a bundle of sensations and that the self is nothing more than this bundle of perceptions connected by an association of ideas. Hume's compatibilist theory of free will takes causal determinism as fully compatible with human freedom. His philosophy of religion, including his rejection of miracles and critique of the argument from design, was especially controversial.