This is an important introduction to and critical interpretation of the work of the major French thinker, Michel Foucault. Through comprehensive and detailed analyses of such important texts as The History of Madness in the Age of Reason, The Birth of the Clinic, The Order of Things, and The Archaeology of Knowledge, the author provides a lucid exposition of Foucault's "archaeological" approach to the history of thought, a method for uncovering the "unconscious" structures that set boundaries on the thinking of a given epoch. The book casts Foucault in a new light, relating his work to Gaston Bachelard's philosophy of science and Georges Canguilhem's history of science. This perspective yields a new and valuable understanding of Foucault as a historian and philosopher of science, balancing and complementing the more common view of him as primarily a social critic and theorist.