This work by the greatest nineteenth-century liberal thinker is one of the founding documents of modern social science, yet its numerous subtle insights and methodological proposals have still not been exhaustively pursued. Mill contends that complex social phenomena cannot be analyzed by casual empiricism or by direct experiment, and that merely "empirical laws" based on historical generalizations must be derivable from a deductive science of human nature. This book also includes an introduction by A. J. Ayer.