This is quite clear from the fact that spirits each have their own idea when anything is said. The idea itself is something general, and, in fact, a very general receptacle of an unlimited number of mental images. So there cannot possibly be a mental image of a thing the very same [as another], even if it appears as a simple idea. For instance, the idea of the human form, of the disposition, of the mind, certainly appears to be a simple one, and yet as many ideas can be contained in it as can ever be thought, which is an infinitude. This can be shown in numerous other instances.