MATTER IS NOT A BODY "WITHOUT QUALITY, BUT WITH MAGNITUDE" (A STOIC DEFINITION).
Besides, how could matter be the first Principle, if it be a body? If the body of which the Stoics speak be of another nature, then matter can be called a body only figuratively.[287] If they say that the common property of the body is to have three dimensions, they are speaking of the mathematical body. If on the contrary they join impenetrability to the three dimensions, they are no more talking about something simple. Besides, impenetrability is a quality, or is derived from a quality; but what is the source of impenetrability? Whence comes tri-dimensional extension? Who endued matter with extension? Matter, indeed, is not contained in the idea of tri-dimensional extension any more than the latter is contained in the notion of matter. Consequently, since matter thus participates in size,[288] it is no longer a "simple" matter.