This account of Hume's philosophy, differs from other books on the subject in two ways. First, Hume's philosophy is set in the context of his whole life's work in the study of "moral subjects" that is areas such as psychology, history, political science and economics. The second approach of this book is that it examines systematically the drastic consequences of accepting not one but three Cartesian presuppositions as "the obvious dictates of reason" which "no man, who reflects, ever doubted". Basically, Hume's starting point in philosophy was the position Descartes reached in Part IV of the "Discourse"; a position quite incomparible with any science, whether moral or natural. The consequences drawn by Hume can, however, be turned round to provide arguments to refute those presuppositions, which are today still widely accepted.