As part of a critical analysis of Paulo Freire's work, this paper argues that, Freire's critical, liberatory pedagogy as conceived in "Education as the Practice of Freedom" (P. Freire, 1982a), coherently systematized in "Extension or Communication" (P. Freire, 1982b) and carried out through "Pedagogy of the Oppressed" (P. Freire, 1974) into his later works (P. Freire, 1992, 1998a; Shor & Freire, 1987), is grounded in a thoroughly Marxist, or dialectical materialist, theory of knowledge (Roberts, 2003). The author contends that an explication of Freire's dialectical materialist epistemology provides for an increased understanding Freire's liberatory pedagogy as a whole because it is difficult to grasp Freire's pedagogy without understanding its Marxism (Allman, 1999). Here, the author's intention is to push in two directions. First, this article serves to provide a detailed, text-based outline of how Freire's pedagogy, at its core, is based on a Marxist, dialectical materialist epistemological view of consciousness, human interaction, and material transformation. The second purpose is to offer a firm defense against many of Freire's detractors, which the author contends, maintain deep misunderstandings of Freire's dialectical materialism and therefore propagate deeply misplaced criticisms of his pedagogical framework. In this paper, the author begins with a very brief discussion of the basic tenets of dialectical materialism. He then follows with a detailed reading of Freire's works, finding textual support for the argument that Freire's epistemological underpinnings were in fact deeply committed to a dialectical materialist philosophical worldview and explains how Freire's conception of liberatory pedagogy flows directly from his epistemological commitments. Finally, the author concludes by arguing that a lack of understanding of Freire's epistemological foundation leads to gross misunderstandings and misrepresentations of Freire's conception of liberatory pedagogy, using work from the collection "Rethinking Freire" (Bowers & Apffel-Marglin, 2005) as an illustration of one such case. (Contains 6 notes.)