Matter, therefore, is necessary to quality as well as to quantity, and consequently, to bodies. In this sense, matter is not an empty name, but a substrate, though it be neither visible nor extended. Otherwise, for the same reason, we would be obliged also to deny qualities and extension; for you might say that each of these things, taken in itself, is nothing real. If these things possess existence, though their existence be obscure, so much the more must matter possess existence, though its existence be neither clear nor evident to the senses. Indeed, matter cannot be perceived by sight, since it is colorless; nor by hearing, for it is soundless; nor by smell or taste, because it is neither volatile nor wet. It is not even perceived by touch, for it is not a body. Touch cognizes only body, recognizes that it is dense or sparse, hard or soft, wet or dry; now none of these attributes is characteristic of matter. The latter therefore can be perceived only by a reasoning which does not imply the presence of intelligence, which, on the contrary, implies the complete absence of matter; which (unintelligent reasoning therefore) deserves the name of "bastard" (or, illegitimate) reasoning.[305] Corporeity itself,[306] is not characteristic of matter. If corporeity be a reason (that is, by a pun, a 'form'), it certainly differs from matter, both being entirely distinct. If corporeity be considered when it has already modified matter and mingled with it, it is a body; it is no longer matter pure and simple. THE SUBSTRATE IS NOT A QUALITY COMMON TO ALL ELEMENTS; FOR THUS IT WOULD NOT BE INDETERMINATE. 13. Those who insist that the substrate of things is a quality common to all elements are bound to explain first the nature of this quality; then, how a quality could serve as substrate; how an unextended, immaterial (?) quality could be perceived in something that lacked extension; further, how, if this quality be determinate, it can be matter; for if it be something indeterminate, it is no longer a quality, but matter itself that we seek. EVEN THIS PRIVATION MIGHT BE CONSIDERED A QUALITY; BUT SUCH A USE OF THE TERM WOULD DESTROY ALL COHERENT REASONING.