This chapter surveys the development of Alasdair MacIntyre’s thought, from his early Master’s thesis through his influential works After Virtue, Whose Justice? Which Rationality?, and beyond. MacIntyre’s intellectual project is aimed at reclaiming moral knowledge; however, it is undermined by his foundational Wittgensteinian commitments. Neither his Aristotelian turn nor his Thomistic turn does anything to counteract this, since both views are grafted into a fundamentally Wittgensteinian outlook. Despite his many attempts to resist, MacIntyre ultimately cannot prevent his view from falling into relativism. He thus fails to reclaim moral knowledge.