David Hume (1711–1776) was the most important philosopher ever to write in English, as well as a master stylist. This volume contains his major philosophical works. A Treatise of Human Nature (1739–1740), published while Hume was still in his twenties, consists of three books on the understanding, the passions, and morals. It applies the experimental method of reasoning to human nature in a revolution that was intended to make Hume the Newton of the moral sciences. Disappointed with the Treatise’s failure to bring about such a revolution, Hume later recast Book I as An Enquiry concerning Human Understanding (1751), and Book III as An Enquiry concerning the Principles of Morals, which he regarded as ‘incomparably the best’ of all his works. Both Enquiries went through several editions in his lifetime.