An extended historical and philosophical argument, this book will be a valuable text for all students of the philosophy of the social sciences. It discusses the serious alternatives to positivist and empiricist accounts of the physical sciences, and poses the debate between naturalism and anti-naturalism in the social sciences in new terms. Recent materialist and realist philosophies of science make possible a defence of naturalism which does not make concessions to positivism and which recognizes the force of several of the anti-positivist arguments from the main anti-naturalist (neo-Kantian) tradition. The author presents a critical evaluation of empiricist and positivist theories of knowledge, and investigates some classic attempts at using them to provide the philosophical foundation for a scientific sociology. He takes the Kantian critique of empiricism as the starting point for the main anti-positivist and anti-naturalist philosophical approaches to the social studies. He goes on to investigate the inadequacy of post-Kantian arguments from Rickert, Weber, Winch and others, both against non-positivist forms of naturalism and as the possible source of a distinctive philosophical foundation for the social studies. The book concludes with a critical investigation of the Marxian tradition and an attempt to establish the possibility of a materialist and realist defence of the project of a natural science of history, which escapes the fundamental flaws of both positivist and neo-Kantian attempts at philosophical foundation.