I. The Opinion of Others

132. [Exposition of the opinion] - Here an affirmative answer is given [Aquinas, Giles, Godfrey], and it is above all held because of the many authorities from Aristotle that seem to have this meaning.

One of these is Metaphysics 7.8.1034a4-8, that the generator generates another because of matter: “Callias and Socrates,” he says, “are diverse because of matter (for they are diverse), but the same in species, for they are individuals of a species.”

133. Again because of 7.11.1037a37-b5, ch. ‘On the Parts of Definition’: “The whatness and the individual are in some substances the same thing, but as to things that are in matter or taken along with matter they are not the same thing;” and 8.3.1043b2-4 seems the same, “For soul and being a soul are the same; man and being a man are not the same, unless being a soul is called man.”     Therefore it seems that matter is outside the idea of quiddity and of whatever first has quiddity, and so, since matter is something in beings, it seems to be part of the individual, or the individuation of the whole; but whatever there is in an individual that is repugnant altogether to the idea of quiddity, this can be posited as the first reason for individuating; therefore etc     .

134. Further 12.8.1074a31-38 proves that there cannot be several heavens: “For if,” he says, “there were several heavens as there are several men, the principle as concerns each would be one in species but many in number; but,” he says, “all things that are many in number have matter; now the whatness does not have matter first (for it is actuality);     therefore the first, immovable mover is one in idea and in number.” This reasoning - whereby the unity of the heaven is proved from the unity of the mover, and the unity of the mover is not only unity in species but in number, because of the fact the mover does not have matter - would not seem valid unless distinction in number were made by matter; therefore etc     .

135. Further On the Heaven 1.9.278a10-15: “When I say ‘heaven’ I state the form; when I say ‘this heaven’ I state the matter.”

136. [Rejection of the opinion] - Against this [n.132], and first through authorities of the same Aristotle:

According to the Philosopher Metaphysics 7.11.1037a5-10, ch. ‘On the Parts of Definition’: “It is clear that soul is substance first and that body is matter; but man or animal - which are from both soul and matter - as universals, and Socrates and Coriscus (supply: from both soul and matter) as singulars; since soul is said in the two ways.” And afterwards he adds: “But if soul is a ‘this’ and body a ‘this’, then as universal and singular.”

137. And previously, in the same place on the parts of definition, 10.1035b27-31: “Man and horse and what thus exist in singulars are not substance universally,” that is, form, “but together a certain whole,” that is, the composite, “made from this matter and this nature” (where he means by the ‘this’ not uniform and singular matter but determinate matter, otherwise he would contradict himself; hence he adds in the same place, “universally”). And he adds later: “From ultimate matter there is now Socrates etc.”

138. The same is also plain from the same Philosopher in 12.5.1071a27-29 where he maintains that the principles are the same just as are the things that come from the principles: “And of those in the same species,” he says, “the principles are diverse, not diverse in species, but because they are principles of singulars; your matter and mover and species are one thing and mine another, but yet the same in universal idea.” So in this way he admits a distinction of form as of matter in the particular, and in this way a unity of matter in general as of form; and therefore the question whereby matter is a ‘this’ must still be asked.

139. Further, as is proved from many places of Metaphysics 7 on the parts of definition: matter is of the essence of the composite substance, namely of man, and such a composite is not precisely the essence of the form. Therefore, just as the composite cannot be of itself a ‘this’ (from the first question, n.29), so neither will the matter -which is part of the composite - be of itself a ‘this’, because there cannot be a composite that is common and of the same idea in diverse things unless whatever is of the essence of the composite can be of the same idea in those diverse things.

140. Further, by reason: matter is the same in the thing generated as in the thing corrupted; therefore it has the same singularity in the thing generated and in the thing corrupted.

141. And if you reply that the matter is not of the same species in the thing generated and in the thing corrupted, I argue as before against non-terminated quantity [n.100], and thus generation will be circular: first of fire from water, second of water from fire; the water corrupted first and the water generated second have the same matter and are of the same species; therefore they are really ‘this water’; therefore the first naturally returns the same in number, which is against what they hold [sc. that matter is the principle of individuation, nn.132].

[N.B. Question Five is Continued after Question Six]