REFUTATION OF STOIC EXPLANATION OF EVAPORATION.
When water flows through wool, or when paper allows water to filter through it, why does not the whole of the water pass through these substances (without partly remaining within them)? If the water remain therein partially, we shall not be able to unite the two substances or masses. Shall we say that the qualities alone are confused (or, mingled)? Water is not in juxtaposition with the paper, nor is lodged in its pores; for the whole paper is penetrated thereby, and no portion of the matter lacks that quality. If matter be united to quality everywhere, water must everywhere be present in the paper. If it be not water that everywhere is present in the paper, but only (humidity which is) the quality of the water, where then is the water itself? Why is not the mass the same? The matter that has insinuated itself into the paper extends it, and increases its volume. Now this augmentation of volume implies augmentation of mass; and the latter implies that the water has not been absorbed by the book, and that the two substances occupy different places (and do not interpenetrate each other). Since one body causes another to participate in its quality, why would it not also make it participate in its extension? By virtue of this union with a different quality, one quality, united with a different one, cannot, either remain pure, or preserve its earlier nature; it necessarily becomes weaker. But one extension, added to another extension, does not vanish.
REFUTATION OF PERIPATETIC EXPLANATION OF EVAPORATION.
One body is said to divide another, by penetrating it. This assertion, however, demands demonstration, for it is more reasonable to suppose that qualities may penetrate a body without dividing it. Such demonstration is attempted by the claim that qualities are incorporeal.[63] But if matter itself be as incorporeal as the qualities, why could not some qualities along with the matter penetrate into some other body? That some solids do not penetrate other bodies, is due to their possession of qualities incompatible with that of penetration. The objection that many qualities could not, along with matter, penetrate some body, would be justified only if it were the multitude of qualities that produced density; but if density be as much of a quality as corporeity, the qualities will constitute the mixture not in themselves alone, but only as they happen to be determined. On the other hand, when matter does not lend itself to mixture, this occurs not by virtue of its being matter, but as matter united to some determinative quality. That is all the truer as matter is receptive to any magnitude, not having any of its own. But enough of this.