The term of practice plays an important role in MacIntyre's philosophy. He uses it in two different ways: either generally as contrast with theory or as a specifically defined term within his Neo-Aristotelianism. These two meanings are independent from each other. The paper is a reconstruction of MacIntyre's argument concerning the notion of practice in its general sense and as related to the concept of theory. First, it analyses practice as opposite to theory, and its Marxist roots; second, it outlines the post-Marxist revolutionary 'Benedictine' vision of MacIntyre's Thomistic Aristotelianism; third, the issue in question is exemplified via the mutual relationship between political philosophy and politics; finally, several implications of the author's argument are suggested. The paper claims that those engaged in elaboration, critique and implementation of political and/or moral theories may benefit from MacIntyre's insightful account of the significance of practice for theory.