Since, therefore, we have sufficiently discussed the nature of place, and it is necessary that a vacuum, if it has a subsistence, should be place deprived of body, and we have shown how place subsists, and how it does not subsist; this being the case, it is evident that a vacuum does not thus subsist, neither considered as separate, nor as inseparable: for a vacuum cannot be a body, but an interval of body. On this account, a vacuum appears to be something, because place also appears to be so; and through the same causes: for those also direct their attention to motion, according to place, who say that place and a vacuum are something beside the bodies that fall into them. But they fancy that a vacuum is the cause of motion in the same manner as that in which a thing is moved; and this resembles what some assert of place. There is not, however, any necessity that if there is motion there should be a vacuum. And, in short, a vacuum can by no means be the cause of every motion, for that reason which was concealed from Melissus: for a plenum may be changed according to quality. Where is it necessary that there should be motion according to place, on account of a vacuum. For bodies which are moved may yield to each other when there is no separate interval beside them. And this also is manifest in the revolutions of things continuous, as likewise in the revolutions of humid natures. Bodies too may be condensed, not into a vacuum but because the things inherent are expelled. Thus, water being compressed, the inherent air is expelled. Things likewise may be increased not only from the ingress of somebody, but also by a change in quality, as if air should be generated from water. And in short the reason concerning increase, and that of water poured upon ashes, are respectively impediments to themselves: for either anything whatever is not increased, or it is not increased by body; or two bodies may be in the same place; (they think fit therefore to solve the common doubt, but they do not demonstrate that there is a vacuum) or it is necessary that all bodies should be a vacuum, if it is every way increased, and is increased through a vacuum. The same reasoning also applies to ashes. That the arguments, therefore, from which they show that there is a vacuum may be easily solved, is evident.
