Beginning with his  http://en.wikipedia.org/wiki/A_Treatise_of_Human_Nature - A Treatise of Human Nature  (1739), Hume strove to create a total  http://en.wikipedia.org/wiki/Naturalism_%28philosophy%29 - naturalistic  " http://en.wikipedia.org/wiki/Science_of_man - science of man " that examined the  http://en.wikipedia.org/wiki/Psychological - psychological  basis of  http://en.wikipedia.org/wiki/Human_nature - human nature . In stark opposition to the  http://en.wikipedia.org/wiki/Rationalists - rationalists  who preceded him, most notably  http://en.wikipedia.org/wiki/Ren%C3%A9_Descartes - Descartes , he concluded that  http://en.wikipedia.org/wiki/Desire - desire  rather than  http://en.wikipedia.org/wiki/Reason - reason  governed human behavior, saying famously: "Reason is, and ought only to be the slave of the passions." A prominent figure in the  http://en.wikipedia.org/wiki/Philosophical_skepticism - skeptical philosophical tradition  and a strong  http://en.wikipedia.org/wiki/Empiricist - empiricist , he argued against the existence of  http://en.wikipedia.org/wiki/Innate_ideas - innate ideas , concluding instead that humans have knowledge only of things they directly experience. Thus he divides perceptions between strong and lively "impressions" or direct sensations and fainter "ideas," which are copied from impressions. He developed the position that mental behavior is governed by "custom";  http://en.wikipedia.org/wiki/Problem_of_induction - our use of induction , for example, is justified only by our idea of the "constant conjunction" of causes and effects. Without direct impressions of a metaphysical "self," he concluded that humans have no actual conception of the self, only of a  http://en.wikipedia.org/wiki/Bundle_theory - bundle of sensations  associated with the self. Hume advocated a http://en.wikipedia.org/wiki/Compatibilism - compatibilist  theory of  http://en.wikipedia.org/wiki/Free_will - free will  that proved extremely influential on subsequent  http://en.wikipedia.org/wiki/Moral_philosophy - moral philosophy . He was also a  http://en.wikipedia.org/wiki/Moral_sense_theory - sentimentalist  who held that ethics are based on feelings rather than abstract moral principles. Hume also examined the normative  http://en.wikipedia.org/wiki/Is%E2%80%93ought_problem - is–ought problem . He held notoriously ambiguous views of  http://en.wikipedia.org/wiki/Christianity - Christianity , ^{http://en.wikipedia.org/wiki/David_Hume#cite_note-1 - [2]}  but famously challenged the  http://en.wikipedia.org/wiki/Teleological_argument - argument from design  in his  http://en.wikipedia.org/wiki/Dialogues_Concerning_Natural_Religion - Dialogues Concerning Natural Religion  (1779).

http://en.wikipedia.org/wiki/Immanuel_Kant - Kant  credited Hume with waking him up from his "dogmatic slumbers" and Hume has proved extremely influential on subsequent philosophy, especially on  http://en.wikipedia.org/wiki/Utilitarianism - utilitarianism , http://en.wikipedia.org/wiki/Logical_positivism - logical positivism ,  http://en.wikipedia.org/wiki/William_James - William James ,  http://en.wikipedia.org/wiki/Philosophy_of_science - philosophy of science , early  http://en.wikipedia.org/wiki/Analytic_philosophy - analytic philosophy , cognitive philosophy, and other movements and thinkers. The philosopher  http://en.wikipedia.org/wiki/Jerry_Fodor - Jerry Fodor  proclaimed Hume's Treatise "the founding document of  http://en.wikipedia.org/wiki/Cognitive_science - cognitive science ." ^{http://en.wikipedia.org/wiki/David_Hume#cite_note-2 - [3]}  Also famous as a prose stylist, ^{http://en.wikipedia.org/wiki/David_Hume#cite_note-3 - [4]}  Hume pioneered the  http://en.wikipedia.org/wiki/Essay - essay  as a literary genre and engaged with contemporary intellectual luminaries such as  http://en.wikipedia.org/wiki/Jean-Jacques_Rousseau - Jean-Jacques Rousseau ,  http://en.wikipedia.org/wiki/Adam_Smith - Adam Smith  (who acknowledged Hume's influence on his  http://en.wikipedia.org/wiki/Economics - economics  and  http://en.wikipedia.org/wiki/Political_philosophy - political philosophy ),  http://en.wikipedia.org/wiki/James_Boswell - James Boswell ,  http://en.wikipedia.org/wiki/Joseph_Butler - Joseph Butler , and  http://en.wikipedia.org/wiki/Thomas_Reid - Thomas Reid .