[Badiou's] mathematics is precise and correct ... I am impressed by the lucidity of [his] remarks on the philosophical significance of category theory, especially in relation to set theory, and I invite philosophically minded mathematicians to be so too.
Notices of the AMS
Battered photocopies of Badiou's hand-drawn primer on category theory were prized possessions among the small group of people in Paris who gathered to attend his Saturday morning seminars in the mid-1990s, and coupled with the companion volume on Being-There also translated here, Topos remains a vital source of information for one of the most important and most challenging sequences of Badiou's philosophical trajectory. In addition to the distinctive light they shed on the transition from volume one to two of Badiou's Being and Event, both these texts are also of great interest and pedagogical value in their own right: non-specialists won't find a clearer, more accessible and more stimulating philosophical introduction to these crucial fields of contemporary mathematics.
Peter Hallward, Author of Badiou: A Subject to Truth and Professor of Philosophy, Kingston University, London, UK.