  The thoroughgoing nature of Gassendi's atomism has led numerous commentators from Descartes to Marx to view him as taking all worldly structures and behaviors to be explicable by the interaction of material bodies.  According to this picture, Gassendi leaves little if any room for the existence of non-material substance or its relevance to metaphysical or natural accounts. One piece of putative evidence for materialism in Gassendi's corpus is his extension of atomist explanation, from all physical phenomena to a large range of non-physical phenomena, including aspects of the mental, social, and ethical. This is not entirely compelling, as we have seen that the material underpinnings of our mental apparatuses is relevant to only some portion of his psychology.