In this book Michel Foucault, one of the most influential thinkers of recent times, calls us to look critically at specific historical events in order to uncover new layers of significance. In doing so, he challenges our assumptions not only about history, but also about the nature of language and reason, even of truth. By analysing the methods of observation that underpinned the origins of modern medical techniques, Foucault is able to identify 'that opening up of the concrete individual, for the first time in Western history, to the language of rationality, that major event in the relationship of man to himself and of language to things'. The scope of such an undertaking is vast, but it is Foucault's skill that, by means of his uniquely engaging narrative style, his penetrating gaze is able to confront our own. After reading his words our perceptions are never quite the same again.