  In Desgabets’s estimation, Descartes’s truly great discovery was his identification of the true nature of sensible qualities (OPD 5: 164).  As Desgabets understood it, sensible qualities “… are nothing else in objects but the local dispositions of the small parts from which result the sensations that we call heat, sound, light, etc.” (OPD 2: 17).  Moreover, sensible qualities qua modes of the mind have no resemblance or similarity to the modes or accidents of matter. Sensible qualities are states or modes of the human mind having only a causal relation to the specific local movements of our sensory organs, which in turn, are the effects of the local movements produced by the arrangements and local dispositions of parts of matter. Unfortunately, the ontological status of these qualities becomes less clear when they are considered as qualities in objects. In this context, for both Descartes and Desgabets, sensible qualities are “various dispositions” in objects. Since Descartes clearly held that sensible qualties are not the forms of material things but rather modes of the mind, the only sense in which sensible qualites could be “in” the various dispositions of objects is in the causal sense, that is, as their effects. While the status and nature of these dispositions in Descartes’s account has been a subject of much debate, it is clear that he distinguished between such qualities as light, colour, smell, taste, sound and touch, which are sensed or perceived qualities, and other qualities, such as size, shape and motion, which are found in all bodies. Descartes wrote that the former qualities are dispositions which depend on size, shape and motion. So, it would seem that for Descartes, secondary qualities are sensible qualities bearing no resemblance to qualities of matter, while primary qualities are qualities belonging to physical objects. 