LESSON 2

Are There Non-Sensible Substances and Principles?

  Chapter 2: 1060a 3-1060b 3

             912. Further, there is the question whether or not we must posit the existence of something besides singular things; and if not, then the science which we are now seeking must deal with these things. But they are infinite in number. And what exists apart from singular things are genera and species; but the science which we are now seeking deals with neither of these. The reason why this is impossible has already been stated (909-911).

             913. And in general the problem is whether one must suppose that there is some substance which is separable from sensible substances (i.e., the things which exist here and now), or that the latter are beings and the things with which wisdom deals. For we seem to be looking for another kind of substance, and this constitutes the object of our study: I mean, to know whether there is something which is separable in itself and belongs to no sensible thing.

             914. Further, if there is another kind of substance apart from sensible substances, from what kind of sensible substances must it be assumed to be separate? For why should we suppose that it exists apart from men and from horses rather than from other animals or non-living things generally? Yet to devise various eternal substances equal in number to sensible and corruptible ones would seem to be unreasonable.

             915. But if the principle we are now seeking is not separable from bodies, what could be more of a principle of things than matter? Yet matter does not exist actually but only potentially; and thus it would seem rather that the specifying principle or form is a more important principle than matter. But the form is corruptible [according to some]; and so in general there is no eternal substance which is separate and exists of itself. But this is absurd; for such a principle and substance seems to exist and is sought by almost all accomplished thinkers as something that exists. For how will there be order in the world if there is not a principle which is eternal, separable and permanent (235-246)?

             916. Again, if there is some substance and principle of such a nature as that now being sought, and this one principle belongs to everything and is one and the same for both corruptible and eternal things, the question arises why it is, if this principle is the same for all, that some of the things which come under it should be eternal and some not; for this is absurd. But if all corruptible things have one principle, and eternal things another, we shall face the same problem if the principle of corruptible things is eternal; for if it is eternal, why are not the things which fall under this principle also eternal? But if it is corruptible, it in turn must have some other principle, and this again must have another, and so on to infinity (250-265).

             917. But on the other hand, if one were to posit those principles which are thought to be the most unchangeable, namely, being and unity, then, first, if each of these does not signify a particular thing or a substance, how will they be separable and exist of themselves? Yet the eternal and primary principles for which we are looking must be such. But if each of these does signify a particular thing or a substance, all beings will be substances; for being is predicated of all things, and unity is predicated of some. But it is false that all beings are substances.

             918. Again, how can the statement of those be true who say that unity is the first principle and a substance, and who generate number as the first thing produced from the unit and matter and say that it is substance? For how are we to understand that the number two and each of the other numbers composed of units is one? For they say nothing about this, nor is it easy to do so.

             919. But if someone maintains that lines and what is derived from these (I mean surfaces) are the first principles of things, these are not separable substances but sections and divisions; the former of surfaces, and the latter of bodies (and points are the sections and divisions of lines); and further they are the limits of these same things. And all of these exist in other things, and none are separable.

             920. Again, how are we to understand that the unit and the point have substance. For every substance is generated but not the point; for the point amounts to a division (266-283).

             921. There is also the problem that, while every science must be about universals and about such and such a universal, a substance is not a universal but is rather a particular and separable thing. Hence, if there is a science of principles, how are we to understand substance to be a principle (288-293)?

             922. Again, the question arises whether or not there is any principle apart from the concrete whole? And by this I mean the matter and what is joined to it. For if not, then everything that is in matter is corruptible. But if there is some principle, it must be the specifying principle or form. Therefore it is difficult to determine in what cases this exists apart and in what not; for in some cases it is evident that the form is not separable, for example, in that of a house (235-247).

             923. Again, there is the question whether principles are the same specifically or numerically? For if they are the same numerically, all things will be the same (248-249).

COMMENTARY

             2173. Having raised a question about the study of this science, Aristotle now raises a question about the things which are considered in this science. He does this, first (912:C 2173), with regard to substances; and second (916:C 2180), with regard to principles ("Again, if").

             In treating the first issue he raises two questions. First, he asks whether or not it is necessary to posit the existence of something else in reality over and above singular things. Now if one claims that it is not, then it seems to follow that the science which we are now investigating must be concerned with singular things. But this seems to be impossible, because singular things are infinite in number, and the infinite is unknowable. And if one claims that it is necessary to posit the existence of something apart from singular things, they must be genera or species; and then this science would deal with genera and species. First, he explains why this is impossible; for it seems that neither genera nor species are principles, yet this science deals with principles.

             2174. The truth of the matter is that in reality there are only singular things, and that anything else exists only in the consideration of the intellect, which abstracts common attributes from particular ones.

             2175. And in general (913).

             Then he states the second question: whether there is some substance which exists apart from sensible substances existing here and now. This question must be raised here because, if there is nothing apart from sensible substances, only sensible substances are beings. And since wisdom is the science of beings, wisdom must be concerned only with sensible substances, even though we seem in this science to be looking for some other separate reality. It belongs to this science, then, to investigate whether or not there is something apart from sensible substances. And whichever alternative is taken, another question arises.

             2176. Further, if there (914).

             He therefore poses the question which seems to arise if one claims that there is something separate from sensible substances. The question is whether this separate thing exists apart from all sensible substances or only apart from some. And if only apart from some, it is hard to explain why we should posit a separate substance apart from some sensible substances and not from others. For there does not seem to be any reason why there should be a separate man and a separate horse apart from the men and horses we perceive by the senses, and why this should not be true also of other animals and other non-living things. But if there is some separate substance apart from all sensible substances, it follows that we must posit the existence of certain separate substances which are eternal and equal in number to sensible and corruptible substances. Thus, just as there is a corruptible man, in a similar way there would be an incorruptible man, and the same with horse and ox, and also with other natural bodies. This seems to be absurd.

             2177. But if the principle (915).

             Then he raises another question which seems to follow if there is no substance separate from sensible substances. This question asks what the first principle is, whether matter or form; for sensible substances are composed of these two principles. For at first glance it seems that nothing can be more of a principle of things than matter, which is the first subject and always continues to exist, as the first philosophers of nature claimed. Yet it would seem that matter cannot be a principle, because it is not an actuality but a potentiality. Hence, since actuality is naturally prior to potentiality, as has been pointed out in Book IX (785:C 1856), the specifying principle or form, which is an actuality, seems to be this principle.

             2178. But it seems that form cannot be a principle because a sensible form appears to be corruptible. If a sensible form were the first principle, then, it would seem to follow that there would be no eternal substance, separable and existing of itself. But this is clearly absurd because some such principle, eternal and separate, and some such substance, is sought by [almost all] the famous philosophers. This is reasonable, for there would not be a perpetual order of things in the world if there were no separate and eternal principle which causes things to be perpetual.

             2179. The true answer to this question is that there are certain substances which are separate from sensible substances; and these are not the Forms of sensible things, as the Platonists claimed, but the primary movers, as will be shown below (1056:C 2492).

             2180. Again, if there (916).

             Then he raises the question about principles. First, he asks what kinds of principles there are; second (917:C 2182), what they are ("But on the other hand"); and third (918:C 2184), how they are related to one another ("Again, how can").

             He accordingly asks (916) whether or not, if there is some separate substance and principle such as we are now seeking, it is the principle of all things, corruptible and incorruptible. Now if there is such a principle of all things, the question arises why some of the things which come from the same principle are eternal and some are not. But if there is one principle for corruptible things and another for incorruptible ones, there remains the question why, if the principle is eternal, the things coming from it are not themselves eternal. But if the principle of things is corruptible, and every corruptible thing is capable of being generated, and everything capable of being generated has a principle, it follows that the corruptible principle will have a principle, and that this will have another, and so on to infinity, as has been made clear above in Book II (153:C 301).

             2181. The truth of the matter is that the first principle of all things is incorruptible, and that some things are corruptible because of their great distance from that principle. These are the things in which generation and corruption are caused by an intermediate cause which is incorruptible as regards its substance but changeable as regards place.

             2182. But on the other hand (917).

             Then he asks what the principles of things are. First, he examines the opinions of those men who claimed that the principles are unity and being because these are the most unchangeable. For no matter how a thing varies, it always remains one.

             2183. But the opinion of these men gives rise to two questions. The first is whether unity and being signify a particular thing, i.e., a substance; for, if they do not, they cannot be separable and exist of themselves. But we are looking for such principles which are eternal and exist separately. Yet if they do signify a particular thing or substance, it follows that all things are substances, and that nothing is an accident; for being is predicated of any existing thing at all, and unity is predicated of some. Now there are some things which involve multiplicity in their being, and the different ways in which unity is predicated truly of these is clear enough. But it is false that all things are substances; and therefore it seems that unity and being do not signify substance.

             2184. Again, how can (918).

             The second question or problem which he raises runs as follows: those who maintain that unity, or the unit, is the principle and substance of things say that number is generated as a first product from the unit and matter. And this, i.e., number, they call substance. But evidently this is not true, because, if a number is composed of the unit and matter, it must be something one, just as what is composed of a living principle and matter must be something living. But in what way is the number two or any other number, which is composed of units, one, as the Platonists claimed? This is not easy to explain, inasmuch as it can be said that they neglected to account for this as though it were easy to understand.

             2185. But if someone (919).

             Second, he examines another opinion about the principles of things. For some claimed that "lines and what is derived from them," namely, surfaces, are principles, because they held that bodies are composed of surfaces, and surfaces of lines. But it is clear that such things are not separate substances which exist of themselves; for such things are sections and divisions: lines being sections and divisions of surfaces, surfaces of bodies, and points of lines. They are also the limits of these things, i.e., points are the limits of lines, and so forth; for a point, which is at the extremity of a line, is the limit of a line. Now what is signified as actually within a line is a section of the line. The same thing is true of a line in relation to a surface, and of a surface in relation to a body; for it is evident that limits and sections are entities which exist in other things as their subjects. Hence they cannot exist apart. Lines and surfaces, then, are not principles of things.

             2186. Again, how are we (920).

             Then he introduces another argument. He says that it cannot be understood that the unit and the point have a substance, because substance begins to exist only by way of generation. But when a line is actually divided, the division itself is a point.

             2187. The correct answer to these questions is that neither units nor lines nor surfaces are principles.

             2188. There is also the problem (921).

             After the question about unity and being and dimensions he now raises the question about substances. First, he asks whether substances are principles. The answer seems to be that they are not; for every science is concerned with universals and with "such and such a universal," i.e., some definite universal subject. Now a substance is not included among universals, but is rather a particular thing which exists of itself. Hence it seems that there is no science of substances. But a science is concerned with principles. Therefore substances are not principles.

             2189. The truth is that, although universals do not exist of themselves, it is still necessary to consider universally the natures of things which subsist of themselves. Accordingly, genera and species, which are called second substances, are put in the category of substance; and of these there is scientific knowledge. And certain things which exist of themselves are principles; and these, because they are immaterial, pertain to intelligible knowledge, even though they surpass the comprehension of our intellect.

             2190. Again, the question (922).

             Second, he asks whether or not there is any "principle apart from the concrete whole," i.e., the natural whole or composite. He explains that by concrete whole he means matter, or the thing composed of matter. For if there is no principle apart from the composite of matter and form, and those principles which are said to be in matter are corruptible, it follows that nothing is eternal. And if there is some principle apart from the composite, it must be the specifying principle or form. Then the question arises in which cases the form is separate and in which it is not. For it is obvious that in some cases the form is not separate; the form of a house, for example, is not separate from matter. It was for this reason that the Platonists did not posit Ideas or Forms of artificial things, because the forms of such things are actualities which cannot exist of themselves.

             2191. The correct answer to this question is that there is some principle apart from matter, and this is not the form of sensible things.

             2192. Again, there is (923).

             He now asks how the principles of all things are related to one another: whether they are the same numerically or only specifically. For, if they are the same numerically, it follows that all things are the same numerically. But if they are not the same numerically, this difference will have to be accounted for.

             2193. The truth is that, if one is speaking of the extrinsic principles of things, they are the same numerically, since the first principle of all things is an agent and final cause. But the intrinsic principles of things--matter and form--are not the same numerically but only analogically, as will be shown below (1049-54:C 2474-87).