diverse in species; namely, for things to involve contrariety when they are contained in the same genus,-things, I say, that are individual. Now, things are the same in species-as many as do not involve contrariety-when they are individual existences; for in division and in media are contrarieties generated, before one comes to those things that are individual.

3. Inference from the foregoing.

Wherefore, it is evident that respecting that which is said to be a genus, neither the same nor diverse in species is any of those things which are adapted for being species as of a genus; for matter is made manifest by negation, and genus is the matter of that of which it is termed a genus-not as the genus of the Heracleids,1 but as that which subsists in Nature. Nor is genus denominated in relation to those that are not contained in the same genus, but in relation to those of which there will be a difference from them in genus; and things differing in species differ from those that are in the same genus: for the difference of that from which it is a difference in species must needs be contrariety, and contrariety belongs to those things that are alone in the same genus.

1. Why contra

to the same

species.

CHAPTER IX.

BUT, perhaps, one would raise the question, ries may belong Why woman does not differ from man in species, when the female and male are contraries, and when contrariety amounts to difference? But neither are female and male diverse in species, although they are the essential differences of animal, and are not as whiteness or blackness, but the male and female are inherent in animal, so far forth as it is animal. Now, the following doubt is almost the same as the foregoing—namely, why it is that contrariety partly makes things diverse in species, and partly does not so; for example, why does it make that which has

1 The Heracleida were the descendants of Hercules, and lords of Peloponnesus. Their place in the history of Greece, and the story of their expeditions, and their varied success, need be no more than alluded to-they are pretty generally known. The best account of the Heracleidæ is to be found in C. O. Müller's History and Antiquities of the Doric Ruce, vol. I. chaps. 3, 11, 12, translated by Messrs. Tufnell and Lewis; the latter the present Sir George Cornewall Lewis, Bart.

of.

the support of feet, and that which is furnished with wings so, but does not make whiteness and blackness? Is 2. Proposed this the case because some things are the proper solution thereaffections of genus, and other things are less so; and since the one is form and the other is matter, as many contrarieties as are contained in form create a difference in species, and as many as reside in form, when assumed together with matter, do not give rise to a specific difference?

whiteness and

man.

Wherefore, whiteness does not give rise to a 3. Illustrated in difference of man, nor blackness; nor are these the case of the specific difference of a white man in relation blackness in a to a black man, nor would one name be assigned to both; for man is as matter, but matter does not create a difference for men are not forms 1 of man. For this reason, although the flesh and bones are diverse from which this man and that are made, yet the entire compound is a thing that is diverse, to be sure, but not different in species, because contrariety does not exist in reason or form, but this entire compound is an individual thing. Now, Callias is form in conjunction with matter; and this, therefore, is the case with white man,-because Callias is white, therefore man is white according to accident. Neither, doubtless, do a brazen and wooden circle, nor a brazen triangle and wooden circle, differ in species on account of matter, but because contrariety is present in the form.

case of horse

But whether shall we say that matter does not 4. Further illus render things diverse in species, though being tration in the somehow diverse itself, or is it the case that it and man commakes them so partly? for why is this horse pared together. diverse from this man in species, and yet the forms of these subsist along with matter? Is it because contrariety is inherent in the form? for there is obviously a contrariety subsisting between a white man and a black horse. And this, at any rate, is a specific difference, but not so far forth as the one is white and the other black; since even if both were white, nevertheless in species they would be diverse. But the male and female are appropriate affections of animal; cording to substance, but in matter and body.

but not acWherefore,

1 Some copies read etôn, and others elde; the Leipsic edition reads ύλη.

I have followed the reading μerà vλns; some MSS. have kara,

the same seed, in consequence of undergoing the same passive condition, is generated either as female or male. What, indeed, therefore, constitutes diversity in species, and why some things differ in species, but others do not, has been declared.

1. Diversity according to genus appertains to contrariety.

CHAPTER X.

BUT whereas contraries are diverse in species, and that which is subject to corruption, and that which is incorruptible, are contraries-for privation is a definite impotentiality—it is requisite that things corruptible be diverse in genus from incorruptible natures.

2. Illustrated

in the case of corruptibles and incorruptibles.

Already, indeed, therefore, have we declared our sentiments respecting these universal appellations.2 So that it would not appear to be necessary that anything whatsoever that is incorruptible and corruptible should be diverse in species; as neither white and black should be so. For it is admissible that the same thing at the same time should be both corruptible and incorruptible, if there may be in subsistence aught of things that are universal, as man would be both white and black; and the case is similar with the mode of the subsistence of singulars, for the same man would not be white and black at the same time, although what is white is contrary to what is black. Of contraries, however, some according to accident are inherent in certain things; for instance, those that have been just now mentioned, and many others: but in the case of others this is impossible-I mean, those to which both that which is corruptible and that which is incorruptible belong; for nothing is corruptible according to accident: for that which is accidental admits of not being; but that which is corruptible belongs to those things which subsist of necessity in those things in which it is inherent, or that which is corruptible will be one

Vide book IV. chaps. xii. and xxii.

2 I presume Aristotle alludes to his investigation in the second book, in his treatment of the question as to whether the first principles of corruptibles and incorruptibles be the same or different? vide chap. iv. of that book, p. 69.

and the same thing with that which is incorruptible, if what is corruptible admits of not being inherent therein. Either, then, substantially, or as inherent in substance, must that which is corruptible subsist in each of the things that are corruptible. But there is the same reasoning, likewise, applicable to the case of that which is incorruptible;1 for both belong to things that possess a necessary existence. So far forth, therefore, as one is primarily corruptible, and the other primarily incorruptible, so far are they in opposition to each other; so that they must needs be generically diverse.

ideal theory.

It is evident, therefore, that it is not possible 3. Such overthat there be such forms as some affirm; for in throws the such a case, as regards man, there will be one who is corruptible, but another who is incorruptible, although forms are said to be the same in species with certain particulars, and not equivocal in respect of them: things that are diverse in genus, however, are at a wider interval from one another than those that are diverse in species.

BOOK X.2

CHAPTER I.

logy already

THAT, indeed, Wisdom is a certain science 1. Questions in conversant about first principles is evident from regard of ontothe early portions of this work, in which doubts discussed. have been expressed respecting statements that have been put forward by others concerning first principles; one, however, would feel doubtful as to whether it would be requisite

'These words are worthy of note, and contain a hint that has been followed up by modern metaphysicians, e. g. Kant.

2 Book X.-according to others book XI.-is occupied in discussions that have already been put forward in the previous portions of the Metaphysics. A glance at the contents will show this. Amongst other topics we have another refutation of Scepticism, in which Protagoras is attacked by name. This subject has been already handled in book III. "Not, however," as Mr. Maurice remarks, "to be passed over on that account; for Aristotle's repetitions of himself, or the reports of his different pupils, generally clear away many difficulties.”

to suppose Wisdom or Ontology to constitute one science br many? For if it does constitute one science, there is, at any rate, one science invariably of contraries; but first principles are not contraries. If, however, it does not constitute one science, as of what quality must we posite these many sciences? Further, to speculate into demonstrative first principles, is it the province of one or of many sciences? for if of one science, why, let me ask, is it the province of this mcre than of any other whatsoever? but if such speculation belong to many sciences, what sort must we consider these to be? Moreover, whether is there one science of all substances, or not? for if there is not one science of all, it would be difficult to render an account of what sort of substances there is one science in existence; if, however, there is one science of all substances, it is an obscure point how it is admissible that there should be the same science of many substances. Further, the question arises as to whether demonstration 2 is conversant about substances only, or also about accidents? for if demonstration be conversant, at least, about accidents, it is not conversant about substances. But if there is one demonstrative science about accidents, and another about substances, what, may I ask, is the character of both, and which of the two constitutes Wisdom or Metaphysics? for demonstrative wisdom is that which is conversant with acci dents; that, however, which is conversant with first principles is the wisdom that takes cognisance of substances.

2. What causes

cerned with?

Neither, however, must we consider the science1 is ontology con- at present under investigation as a science respecting the causes that have been already enumerated in our treatise on Physics. For neither should we act thus in regard of "the final cause;" for a thing of this kind is that which is good: and this resides in practical things, and in those entities that are in motion; and this imparts motion in the first instance, for the end is a thing of this sort but the imparter of motion in the first instance does not inhere in those things that are incapable of motion.

1 Although most of the subjects treated of in this book have been investigated already, yet the analysis of motion, and the Aristotelian theory of the Infinite, found therein, are quite new,

2 Vide Posterior Analytics, book II. chap. iii.

Vide book V. chaps. ii. and iii.

4 Vide book I. chaps. i. and i