This book offers a straightforward account of Sir Karl Popper's views on scientific methodology ranging from Logik der Forschung in 1934 to A World of Propensities in 1990. Part I covers his treatment of the interrelations between metaphysics and science, the fallacies of induction, the method of conjectures and refutations, evolutionary epistemology, the propensity theory of probability, and the interpretation of quantum mechanics. Part II considers the problems of the social sciences, his critiques of historicism and holistic planning, his defence of piecemeal planning on both...