To reach knowledge of the true nature of material objects, one must consider their being in relation to their substance alone.

This does not mean that the senses cannot access the true nature of things as well. In fact, for Desgabets, since all knowledge comes from the senses, the function of knowing the essences of things is a necessary role served by the senses. Recall that the true nature of particular objects consists in the local dispositions of parts of matter which produce the course of the movements we experience. These movements are the first and sole contact we have with the material world, and so the senses p