The work of Roy Bhaskar has had far-reaching effects in the philosophy of science and for political and moral theories of human emancipation. It shows how to overcome the atomistic and narrowly human-centered approaches which have dominated European thought for four centuries. In this readable introduction to his work, Andrew Collier expounds and defends the main concepts of Bhaskar’s philosophy. The first part of this book looks at the philosophy of experimental science and discusses the stratification of nature, showing how biological structures are founded on chemical ones yet are not reducible to them. This paves the way, in part two, for a discussion of the human sciences which demonstrates that the world they study is also rooted in and emergent from nature. Bhaskar’s concept of an “explanatory critique” (an explanation that is also a criticism, not in addition to, but by virtue of, its explanatory work) is discussed at length as a key concept for ethics and politics. Collier concludes by looking at the uses to which critical realism has been put in clarifying disputes within the human sciences with particular reference to linguistics, psychoanalysis, economics and politics.