Any serious attempt to explain social life has come to terms with socilogy's positivist legacy. Yet every debate about the relation between positivism and sociology is clouded by the diversity of uses of the term "positivism". The merit of this book is that it makes this diversity its central theme: it reviews 12 conceptions of positivism that have emerged since the mid-19th century. The discussion charts the changing positivist views about laws and explanation, causality, empirical evidence and theory. It concludes by reviewing current controversies about the place of positivism in sociology.