LESSON 10

Meanings of Substance

Chapter 8: 1017b 10-1017b 26

             440. The term substance (substantia) means the simple bodies, such as earth, fire, water and the like; and in general bodies and the things composed of them, both animals and demons and their parts. All of these are called substances because they are not predicated of a subject, but other things are predicated of them.

             441. In another sense substance means that which, being present in such things as are not predicated of a subject, is the cause of their being, as the soul in an animal.

             442. Again, substance means those parts which, being present in such things, limit them and designate them as individuals and as a result of whose destruction the whole is destroyed; for example, body is destroyed when surface is, as some say, and surface when line is. And in general it seems to some that number is of this nature; for [according to them] if it is destroyed, nothing will exist, and it limits all things.

             443. Again, the quiddity of a thing, whose intelligible expression is the definition, also seems to be the substance of each thing.

             444. It follows, then, that the term substance is used in two senses. It means the ultimate subject, which is not further predicated of something else; and it means anything which is a particular being and capable of existing apart. The form and species of each thing is said to be of this nature.

COMMENTARY

             898. Aristotle now explains the various senses in which the term substance is used; and in regard to this he does two things. First (440:C 898), he gives the various senses in which the term substance is used. Second (444:C 903), he reduces all of these to two ("It follows").

             In treating the first part he gives four senses of the term substance. First, it means particular substances, such as the simple bodies: earth, fire, water and the like. And in general it means all bodies, even though they are not simple, i.e., compound bodies of like parts, such as stones, blood, flesh and the like. Again, it means animals, which are composed of such sensible bodies, and also their parts, such as hands and feet and so on; "and demons," i.e., the idols set up in temples and worshipped as gods. Or by demons he means certain animals which the Platonists claimed are capable of reasoning, and which Apuleius defines thus: demons are animals composed of an ethereal body, rational in mind, passive in soul, and eternal in time. Now all of the foregoing things are called substances because they are not predicated of another subject but other things are predicated of them. This is the description of first substance given in the Categories.

             899. In another sense (441).

             He says that in another sense substance means the cause of the being of the foregoing substances which are not predicated of a subject; and it is not extrinsic to them like an efficient cause but is intrinsic like a form. It is in this sense that the soul is called the substance of an animal.

             900. Again, substance (442).

             He gives a third meaning of substance, which is the one used by the Platonists and Pythagoreans. He says that all those parts of the foregoing substances which constitute their limits and designate them as individuals, according to the opinion of these thinkers, and by whose destruction the whole is destroyed, are also termed substances. For example, body is destroyed when surface is, as some say, and surface when line is. It is also clear that surface is the limit of body and line the limit of surface. And according to the opinion of the philosophers just mentioned the line is a part of surface and surface a part of body. For they held that bodies are composed of surfaces, surfaces of lines, and lines of points; and thus it would follow that the point is the substance of the line, the line the substance of surface, and so on for the rest. And according to this position number seems to constitute the entire substance of all things, because when number is destroyed nothing remains in the world; for what is not one is nothing. And similarly things which are not many are non-existent. And number is also found to limit all things, because all things are measured by number.

             901. But this sense of substance is not a true one. For that which is found to be common to all things and is something without which they cannot exist does not necessarily constitute their substance, but it can be some property flowing from the substance or from a principle of the substance. These philosophers also fell into error especially regarding unity and number because they failed to distinguish between the unity which is interchangeable with being and that which is the principle of number.

             902. Again, the quiddity (443).

             He says that the quiddity of each thing, which the definition signifies, is also called its substance. Now the quiddity or essence of a thing, whose intelligible expression is the definition, differs from a form, which he identified with the second meaning of substance, just as humanity differs from a soul, for a form is part of a thing's essence or quiddity, but the essence or quiddity itself of a thing includes all its essential principles. It is in this last sense, then, that genus and species are said to be the substance of the things of which they are predicated; for genus and species do not signify the form alone but the whole essence of a thing.

             903. It follows (444).

             Then he reduces the foregoing senses of substance to two. He says that from the above-mentioned ways in which the term substance is used we can understand that it has two meanings. It means the ultimate subject in propositions, and thus is not predicated of something else. This is first substance, which means a particular thing which exists of itself and is capable of existing apart because it is distinct from everything else and cannot be common to many. And a particular substance differs from universal substance in these three respects: first, a particular substance is not predicated of inferiors, whereas a universal substance is; second, universal substance subsists only by reason of a particular substance, which subsists of itself; and third, universal substance is present in many things, whereas a particular substance is not but is distinct from everything else and capable of existing apart.

             904. And the form and species of a thing also "is said to be of this nature," i.e., substance. In this he includes the second and fourth senses of substance; for essence and form have this note in common that both are said to be that by which something is. However, form, which causes a thing to be actual, is related to matter, whereas quiddity or essence is related to the supposit, which is signified as having such and such an essence. Hence "the form and species" are comprehended under one thing--a being's essence.

             905. He omits the third sense of substance because it is a false one, or because it is reducible to form, which has the character of a limit. And he omits matter, which is called substance, because it is not substance actually. However, it is included in the first sense of substance, because a particular substance is a substance and is individuated in the world of material things only by means of matter.