from Kevin M. Brien's MARX, REASON, AND THE ART OF FREEDOM, 2nd ed. (Humanity Press, 2006), p. 1:
"... the [humanistic Marxian] usage of the phrase 'being-in-the-world' in the discussion that follows is very different from Heidegger's conception... [His] conception ... is a phenomenological one which would conflate the ontological into the phenomenological. However, the conception ... introduced here is ... an ontological conception that would resist conflation into the phenomenological. It is a much broader conception than Heidegger's... For, although it takes account of phenomena, it is also concerned to get at the essential structures of reality on the basis of which the phenomena come to be the phenomena. It can be considered as a fundamental ontological postulate concerning the relation between mind and body, and between other minds and bodies. And it is a postulate of both theoretical and practical reason as interpreted in a dialectical-humanist universe of discourse."
To my mind, this says that H's B-I-T-W combines ontology and epistemology, but that Brien's B-I-T-W separates these.
Some may like the book's later argument (in an appendix) that Marx and Buddha present complementary perspectives. -- Jim Devine / "The crippling of individuals I consider the worst evil of capitalism. Our whole educational system suffers from this evil. An exaggerated competitive attitude is inculcated into the student, who is trained to worship acquisitive success as a preparation for his future career." -- Albert Einstein.