Hume's excellent account of human nature and mental functioning is published here complete and inclusive of original notes. Often referred to as simply 'The Enquiry', this work is notable for setting forth a number of the concepts which would come to define David Hume's contribution to empirical philosophy. Although selling poorly at the time of first publication in 1748, this book found recognition following Hume's death as his ideas became increasingly appreciated in academic circles. An Enquiry Concerning Human Understanding has an intuitive layout - commencing with an introduction to the philosophic matters at hand, Hume delves incrementally into his beliefs on the nature of the human being. The means by which people mentally formulate ideas occupies a large tract of the work, while the process of learning, assimilating and memorising information is also discussed. Later chapters focus on abstract topics, including the relation of probability to human activity, the inter-relatedness of individual ideas, and the merits of societal liberty in allowing man to exert his free will. Comparisons of human perception and behaviour with members of the animal kingdom, together with an examination of human testimony in the context of miraculous events, are also present. Today, this work by Hume is considered a classic of Enlightenment era philosophy, and remains a required text in many university courses.