The Archaeology of Knowledge begins with a review of methodologies adopted by contemporary historical writing, but it quickly becomes clear that this is part of a far bigger concern. As in much of Foucault's writing, a meticulous attention to the detail of history is accompanied by an aspiration to change not just what is thought but the terms or conditions in which thought takes place. To appreciate the aims of this book, one therefore has to consider the currents of history in which it moves, and these are defined above all by the problem to which it responds. As I set out in the Introduction, in Foucault's view thinking in modernity had become caught in an impasse from which it could not escape without undergoing a radical change, one to which The Archaeology of Knowledge is intended to add its own impetus. To make sense of this book one therefore must also place oneself in the future it works to open up. Saying this might imply that one has to take sides and either fail to understand his approach or endorse it fully, surrendering a critical perspective on what it achieves and on its methods. But this is not the case; in fact, nothing would be more alien to Foucault's own way of thinking. It simply means that what Foucault tries to do in The Archaeology of Knowledge does not make sense from the standpoint of the historical situation to which it responds. In this respect, the book has the character of an intervention and one has to be prepared for the framework of historical and philosophical thought it engages to be modified in some way.