Alain Badiou is arguably the most important and original philosopher working in France today. Swimming against the tide of postmodern orthodoxy, Badiou's thought revitalizes philosophy's perennial attempt to provide a systematic theory of truth. This volume, assembled with the collaboration of the author, presents a comprehensive outline of Badiou's ambitious system. Starting from the controversial assertion that ontology is mathematics, it sets out the theory of the emergence of truths from the singular relationship between a subject and an event. Also included is a substantial excerpt from Badiou's forthcoming work on the logics of appearance and the concept of world, presented here in advance of its French publication. Ranging from startling re-readings of canonical figures (Spinoza, Kant and Hegel) to decisive engagements with poetry, psychoanalysis and radical politics, "Theoretical Writings" is an introduction to one of the great thinkers of time.