  At first glance, Desgabets’s analogy between attributing a corporeal nature to thoughts and attributing a duration or division to things serves more to confuse than clarify. But if we draw on his earlier point about the true nature of individual bodies, we can make some sense of it. Recall that individual bodies are real in that they result from the division of matter by motion into assemblages of local dispositions of parts of matter. Bodies then act upon our sensory organs which in turn are received as ideas in the mind. But the individuation of perception into sensible ideas of bodies is essentially an operation performed by the mind, even though it has its foundation in the local dispositions of matter itself. For example, our perception of a ten foot pole is the effect of a specific assemblage of local dispositions of matter acting upon our sensory organs at a certain time and the mind’s division of that sensible body into ten feet. The local disposition itself is not intrinsically a pole, or ten feet long, but it is so extrinsically, that is, by thought. Similarly, thoughts themselves are not intrinsically extended or subject to movement, but they are so extrinsically, that is, as an effect of the operations of the sensory organs of the body. In other words, just as the local movements of matter individuate thought extrinsically giving the mind individual thoughts, the thought of immaterial substance individuates matter extrinsically thereby giving it perceptions of individual bodies. The mind-body union, and the essential intentionality which results from it, create the mutual dependence of the operations of mind and matter without requiring that mind be material or matter be immaterial.