‘Theory of what?’ is the obvious lay response to Philipp Felsch’s title. But for those in the know, it goes without saying that he is talking about Theory with a capital T. That strange hybrid of philosophy, ethnology, and literary criticism cast its spell over participants in the student movement in Germany from the mid-1960s and in Paris after 1968. In the 1980s and 1990s, it reached the humanities departments of Anglophone academia, making a PhD dissertation without a Theory component a risky undertaking. This applied even in history, traditionally the most empirical of disciplines; and in 1994, Keith Windschuttle, soon to be prominent in the Australian ‘history wars’ about the interpretation of European colonisation, was provoked to write a whole book entitled The Killing of History: How a discipline is being murdered by literary critics and social theorists.