This paper analyses the development of the schism between Marxism and anarchism and explores two distinct methodological approaches to investigating these apparently discrete ideologies: one is derived from analytic political philosophy; the other is an adaptation of Michael Freeden’s conceptual approach. The former views the division between Marxism and anarchism as the result of a clear distinction in universal principles, an account that is found to be flawed. Using the alternative conceptual approach, this paper argues that the schism that marked the relationship between anarchism and Marxism during the ‘short twentieth century’ was primarily the result of the primacy Marxism gave to the Leninist centralized structure following the Bols...