Approaching Alain Badiou as a militant thinker who wages theoretical battles to advance the communist hypothesis, this book explores the central ambiguity of his project: the enigmatic relationship between philosophy and politics. On the one hand, Badiou's mature texts maintain a strict line of separation between the two thought-practices. On the other, he consistently links the philosophical pursuit of true life to a political revolt against injustice and domination. By making a case for the French philosopher as a combative polemicist rather than a builder of grand ontological systems, The Philosophical Militant advances a new imperative for philosophy – to privilege active engagement with the present. Tracing Badiou's engagement with canonical philosophers, putting him in dialogue with contemporary theorists, and exploring the relevance of his ideas to the politics of Trump and the COVID-19 pandemic, this text foregrounds the actuality of Badiou's work. Not limiting itself to commentary on the philosopher's canonical texts, Gordienko aspires to think the contemporary moment with Badiou.