This book gives a unique historical and interpretive analysis of a widely pervasive mode of thought that it describes as the legacy of positivism. Viewing Auguste Comte as a pivotal figure, it charts the historical origins of his positivism and follows its later development through John Stuart Mill and Émile Littré. It shows how epistemological shifts in positivism influenced parallel developments in the human and legal sciences, and thereby treats legal positivism and positivism as it is understood in the human sciences within a common framework.