Summary (of Doctrine) Regarding the Father, the Son, and the Holy Spirit, and the Other Topics Discussed in the Preceding Pages.
33 And, in the first place, it is to be noted that we have nowhere found in the canonical Scriptures, up to the present time, the word “matter” used for that substance which is said to underlie bodies. For in the expression of Isaiah, “And he shall devour ὕλη,” i.e., matter, “like hay,” when speaking of those who were appointed to undergo their punishments, the word “matter” was used instead of “sins.” And if this word “matter” should happen to occur in any other passage, it will never be found, in my opinion, to have the signification of which we are now in quest, unless perhaps in the book which is called the Wisdom of Solomon, a work which is certainly not esteemed authoritative by all. In that book, however, we find written as follows: “For your almighty hand, that made the world out of shapeless matter, wanted not means to send among them a multitude of bears and fierce lions.” Very many, indeed, are of opinion that the matter of which things are made is itself signified in the language used by Moses in the beginning of Genesis: “In the beginning God made heaven and earth; and the earth was invisible, and not arranged:” for by the words “invisible and not arranged” Moses would seem to mean nothing else than shapeless matter. But if this be truly matter, it is clear then that the original elements of bodies are not incapable of change. For those who posited “atoms”— either those particles which are incapable of subdivision, or those which are subdivided into equal parts— or any one element, as the principles of bodily things, could not posit the word “matter” in the proper sense of the term among the first principles of things. For if they will have it that matter underlies every body— a substance convertible or changeable, or divisible in all its parts— they will not, as is proper, assert that it exists without qualities. And with them we agree, for we altogether deny that matter ought to be spoken of as “unbegotten” or “uncreated,” agreeably to our former statements, when we pointed out that from water, and earth, and air or heat, different kinds of fruits were produced by different kinds of trees; or when we showed that fire, and air, and water, and earth were alternately converted into each other, and that one element was resolved into another by a kind of mutual consanguinity; and also when we proved that from the food either of men or animals the substance of the flesh was derived, or that the moisture of the natural seed was converted into solid flesh and bones—all which go to prove that the substance of the body is changeable, and may pass from one quality into all others.
34. Nevertheless we must not forget that a substance never exists without a quality, and that it is by an act of the understanding alone that this (substance) which underlies bodies, and which is capable of quality, is discovered to be matter. Some indeed, in their desire to investigate these subjects more profoundly, have ventured to assert that bodily nature is nothing else than qualities. For if hardness and softness, heat and cold, moisture and aridity, be qualities; and if, when these or other (qualities) of this sort be cut away, nothing else is understood to remain, then all things will appear to be “qualities.” And therefore also those persons who make these assertions have endeavoured to maintain, that since all who say that matter was uncreated will admit that qualities were created by God, it may be in this way shown that even according to them matter was not uncreated; since qualities constitute everything, and these are declared by all without contradiction to have been made by God. Those, again, who would make out that qualities are superimposed from without upon a certain underlying matter, make use of illustrations of this kind: e.g., Paul undoubtedly is either silent, or speaks, or watches, or sleeps, or maintains a certain attitude of body; for he is either in a sitting, or standing, or recumbent position. For these are “accidents” belonging to men, without which they are almost never found. And yet our conception of man does not lay down any of these things as a definition of him; but we so understand and regard him by their means, that we do not at all take into account the reason of his (particular) condition either in watching, or in sleeping, or in speaking, or in keeping silence, or in any other action that must necessarily happen to men. If any one, then, can regard Paul as being without all these things which are capable of happening, he will in the same way also be able to understand this underlying (substance) without qualities. When, then, our mind puts away all qualities from its conception, and gazes, so to speak, upon the underlying element alone, and keeps its attention closely upon it, without any reference to the softness or hardness, or heat or cold, or humidity or aridity of the substance, then by means of this somewhat simulated process of thought it will appear to behold matter clear from qualities of every kind.
Source: De Principiis (New Advent)