Division of Labor, Mental, Material

As is the case in several sections of the German Ideology, Marx-Engel's attempt to derive a separation of mental labor from physical labor is methodologically sloppy.  For, it presupposes a distinction of "material" and "mental", that, especially in the context of an apparent subscription to a Materialist concept of Mind, itself requires further elucidation.  Now, one approach to such a derivation that is seemingly consistent with some of the principles of Marxism, is to begin with the concept of Labor, and analyze it as "intelligent motion".  Accordingly, the separation, and its hypostasization, of the latter two terms produces a 'mental-'material' duality, plus, it is also produces a division of Labor.  However, as rigorous and potentially fruitful for Marxism as such a derivation might be, that it is adequate without the concept of Dialectical Materialism likely disqualifies it from serious consideration among Marxists.