This books explore the relevance and application of the conceptual and theoretical works of Michel Foucault to an understanding of modern society. The book begins by providing a biographical excursion of Foucault's life and works that gives the reader hints of how this thinking of social theory was shaped. The book moves its attention to how conceptual tools he developed are relevant to modern social theory and the interpretation of people, professions and populations in western culture in particular. The book explores the impact of his work on power and the example of social work and how it reshaped such a helping profession. In doing so, Foucault raised both a challenge and impact for social theorists to take up on subjectivity in how individuals make their own histories. Despite this, the book concludes with a re-appraisal of Foucault's work on surveillance and aging prisoners that highlights the sheer analytical diversity of his social philosophy.