Proposition 28

194. Every substance that stands through its essence is simple and is not divided.

195. This is because if someone were to say: it is possible that it be divided, we would say, if it is possible that a substance that stands through itself be divided and itself be simple, it is possible that the essence of part of it exist through its essence again as if it were the essence of the whole. Thus if that is possible, the part returns upon itself, and every one of its parts is returning on itself, just as if it is a return of the whole over its essence; and this is impossible. Thus if this is impossible, a substance that stands through itself is indivisible and is simple.

196. But if it is not simple but is composite, one part of it is better than another part and one part of it is worse than another part; Thus a better thing comes from a lesser thing and a lesser thing from a better thing, insofar as every one of its parts is separated from every other.

197. Because of this its uniformity is not sufficient by itself, since it is in need of its parts from which it is composed. And moreover this does not fit the nature of a simple thing, but rather it is of the nature of composite substances.

198. Thus it is now agreed that every substance that stands through its essence is simple and is not divided; and, insofar as it does not receive division and it is simple, it does not admit of corruption or destruction.

421. After he has followed up on the diversity of substance according to generation and corruption, here (194) he follows up concerning the diversity of substance which can be considered according to simplicity and composition, and he brings to this point two propositions, of which the second (190) seems to be the converse of the first.

422. So, the first is like this: every substance standing through its essence is simple and is not divided. This proposition is also posited in the book of Proclus in proposition 157 under these words: every autohypostatic is indivisible and simple.

423. Where, first it should be considered that simple and indivisible is the same in subject, but they differ in definition: for something is called indivisible through a privation of division, because, that is to say, it is not divisible into many; now, something is called simple, through privation of composition, because, that is to say, it is not composed out of many.

424. First, therefore, it is proved that a substance standing by itself is indivisible (195);

second, that it be simple (196).

425. Now the first is better proved in Proclus' book than here: for this is his proof (Elements of Theology, 157): for if, he asks, it is divisible, being autohypostatic, that is, subsisting by itself, it would establish itself as divisible and turn its whole self to itself and all in all of itself will be; but this is impossible; therefore the autohypostatic is indivisible.

426. As evidence for this, it should be considered that here it is accepted that there is something standing by itself, not by reason of its parts: as, that is, one part of it would stand through another, just as happens in material substances, but by reason of the whole: as, that is, the whole stands whole through itself. Now, each one is turned to it because it stands just as an effect to a cause and it is necessary that it be in it just as in its grounding. Therefore, if something divisible should be standing through itself, it would be necessary that every part of it stand through each, and each be grounded in each. Which is impossible: because thus it would follow that one and the same part of it would be cause and effect at the same time and in respect of the same thing; which is impossible.

427. Now in this book, it is proved thus: that which is proper to something through itself belongs to each part of it, if it be divisible. If, therefore, something divisible be standing through itself, it is necessary that each part of it stand through itself and thus it would not support itself on another for the constitution of the whole.

428. But this proof is not so efficacious, because it is not necessary, that what belongs per se to the whole of something, belong to its individual parts: for there is a certain whole of similar parts, like air and water; and certain of dissimilars, like animal and house.

429. Now, that that which is standing by itself be simple, that is, not composed out of many, is proved by a double reason.

In everything composed out of many parts, it is necessary to posit a certain order of the parts, so that, to be precise, one part of it be better and another worse (196). For many things come to be constituted as one in a certain order, just as also a multitude proceeds from one in a certain order. Whence we see that in the composition of a natural body, the form is what exists before matter and in the composition of a mixed body, one element is dominant and in the composition of the parts of an animal one member is more principal than another and in the parts of any one continuous thing, one part is closer to the point which is the principle of magnitude than the others. Therefore, if anything composed out of many parts be standing through itself, it will be necessary that each part of it be standing out of each, and so a better part will depend on a worse part and vice-versa.

430. The second reason (197) is because everything which is standing through itself is sufficient for itself in its own being, not lacking another for its substance; by which dependence from an agent cause is not excluded, but dependence from a formal and material cause existing before the substance.

431. Now, everything composed out of parts is not sufficient to itself, but it needs for its subsistence the parts out of which it is composed, which behave in the habitude of a material cause to the whole. Therefore, nothing composed out of parts is standing by itself. Therefore every substance standing by itself is simple.

432. Nevertheless it should be known that this second reason (197) is posited distinctly in Proclus' book, but in this book it is brought in by the mode of a conclusion.