needs be an end, and, in the other case, the things adduced revert into one another, for the destruction of one is the generation of the other. But at the same time, also, it is impossible, that what is first, seeing that it is eternal, should be subject to corruption; for since generation is not infinite in an ascending progression, that nature must needs not be eternal from which anything has been produced as from that which is primary, and has been subject to corruption; but this is impossible.

the case of the

cause.

Further, the final cause is an end; but a thing 5. No infinite of this sort is that which does not subsist on progression in account of another, but other things on account final or formal of that. Wherefore, if that which is last be a thing of this sort, there will not be a progression to infinity; but if there is no such thing-I mean that which is last— the final cause will have no existence. But they who introduce this infinite progression forget that they destroy the nature of the good. Although no one would undertake entering on any course of action not intending to go on to a termination of his undertaking; nor would there be design in such things: for one who is possessed of mind always does a thing for some purpose or other, (for this is a termination for it,) for the end proposed is a termination. But, indeed, neither can the formal cause admit of being referred to another definition more copious in reason. For the prior definition is invariably more the definition of a thing; but the subsequent is not so. But to that of which there is no first, neither has that which is next in order any existence. Further, they destroy scientific knowledge who make assertions in this way; for it is not even possible to understand anything before we come to individual things; and scientific knowledge has no existence in this case: for things infinite, in this manner, how is it possible to apprehend? for the infinite here is not a thing similar to infinity in the case of a line, which, as regards its divisions, indeed, does not come to a stand-still, but is indivisible; nor is it possible for one to apprehend these divisions, except he imposes some limit to their divisibility. Wherefore, he will not reckon the divisions or sections who goes through the infinite in detail. But also, as regards the matter,-so far as it is such, in what ie

6. This theory

of infinite pro

gression would overturn the

possibility of knowledge.

being moved,1--it is necessary to understand it thus far; and for nothing that is infinite is there any possibility of existence: but, if this is not the case, not infinite, at any rate, is that by which we may know the infinite. But, doubtless,

if the species of causes were infinite in number, neither, in such a case, would the perception of our knowledge be possible; for then we think we know when we may make known the causes but the infinite according to addition, it is not in finite duration possible to exhaust.

1. The influence of habit on our speculative opinions.

CHAPTER III.2

BUT lectures on philosophic subjects fall out according to our habits; for as we have been accustomed, so we deem it right a thing should be expressed; and whatever things are besides these do not appear similar: but, from the fact of our not being habituated thereto, they seem more unknown and strange, for the habitual is more known. And how great force the habitual possesses, the laws make manifest, in which fabulous and puerile things have greater force from usage than the reality of our knowledge concerning them. 2. Different de- But some persons, indeed, do not admit those grees of preci- making assertions, unless one speaks with mathematical precision; but others do not approve of what is said, unless they express themselves by means of an exemplar; and others think it right to adduce a poet as a witness. And some require all things to be expressed with accuracy; whereas accuracy is troublesome to others, either on account of their not being able to carry on

sion in different kinds of science.

1 "In what is being moved." Some read, Kivovμévny: meaning, that matter is not infinite in the sense of things that might be said to be infinite in energy.

2 The subject now treated of is also discussed in his Ethics. His reasoning here has been adopted by all subsequent philosophers: .g. Bishop Butler; vide Preface to his Sermons, and part II. chap. ii. of the Analogy.

3 This is illustrated in the fable of the earth being the mother of the human race, which was recognised in the Athenian and Spartan laws. We, accordingly, find Plato recommending the recognition of this myth in the legislative system of a people, since thereby would be secured amongst them patriotism and a love of country.

3. The na

a train of reasoning, or on account of their considering such as mere quibbling about verbal niceties,—for the precise involves some such thing. Wherefore, as in the case of con. tracts, so also in that of philosophic discourses, precision seems to be a thing to some persons that is illiberal. Wherefore, it is necessary that one should have been instructed what way we must admit each turalist is not and all points of inquiry, as it would be absurd expected to em ploy mathemaat the same time to seek for scientific knowledge tical accuracy and the mode of attaining such knowledge: but of language. it is not easy to acquire either of these. Now, mathematical accuracy of language2 is not to be required in all things, but in those things that do not involve any connexion with matter. Wherefore, such is not the natural mode of discovering truth;" for perhaps the whole of Nature involves matter: therefore, first must we investigate what Nature is.1 For in this way, also, will it be evident about what only natural science is conversant, and whether it is the province of one science, or of many, to speculate into causes and first principles.

1 èπl Tŵv Abywv. I have translated these words "discourses," following the Latin "orationibus." The term which Aristotle already has used, in the beginning of the sentence, is depoάoes, which I have rendered "lectures." This term has given rise to the distinction of the Aristotelian writings into acroatic and exoteric.

2 As to the different sorts of accuracy requisite for the treatment of different departments of human knowledge, the student is referred to Ethics, I. iii., and to Post Analyt. I. 13, 24.

3 That is, the mode of discovering truth adopted by the natural philosopher.

4 "What Nature is." These words have led commentators to form the surmise that this is a fragmentary portion of some physical treatise. It is worthy of remark, too, that this book is said not to have been written by Aristotle at all, but by one styled Pasicles, a native of Rhodes, who is said to have been a hearer of Aristotle, and a son of Bonus or Boethus, a brother of Eudemus.

BOOK II'

1. Doubt-its relation to

CHAPTER I.

FOR the advancement of the science under investigation it is necessary for us, first, to take scientific truth. a review of those points respecting which one ought to doubt in the first instance; but these are whatsoever subjects some speculators have entertained opinions of after a different mode, and whatever beyond these may happen to have been overlooked. For it will contribute towards one's object, who wishes to acquire a facility in the gaining of knowledge, to doubt judiciously, for a subsequent acquisition 2 in the way of knowledge is the solution of previous doubts; but when one is ignorant of the bond of a thing, it is not possible for such to loose it. But the perplexity of the intellect makes manifest this assertion respecting the matter in hand; for so far forth as the dianoetic faculty doubts, so far does it undergo something similar to persons loaded with chains; for it is impossible, in both cases, to advance further. Wherefore, it is necessary, in the first instance, to speculate into all the difficulties involved in the present subject, both on account of these things, and also from the fact, that they who carry on an investigation, without doubting first, are similar to persons ignorant where they ought to walk; and, in addition to these things, neither can such know whether he has discovered the object of his speculation or not; for the end is not manifest to this speculator: but to one who has previously doubted, in a judicious way, it is manifest. But,

This book, if we allow what is commonly called Book I. the Less to be as a separate one and as book II., would, in this case, stand third in order, which it does in some of the MSS. In this book, however, Aristotle proceeds, according to the hint dropped at the end of the first book, to lay before his readers, after the mode usually adopted by dis putants in the schools, the doubts suggested to a thinking mind, as connected with the subject-matter of ontological or metaphysical science.

2 This idea, according to Asclepius, is taken by Aristotle from Plato, who pithily illustrates it by the case of fire being the result of the rub bing together of two sticks.

2. Is the science

science of onto

further, there is a necessity that a person saould be better qualified for forming a judgment who has heard all the reasons, as it were, of adversaries and opposing disputants. Now, the first source of perplexity is concerning those things which we have expressed doubts of causes, as a of in our Preface; namely, whether to speculate logy, to be reinto causes1 be the province of one or many garded as one or many! sciences? and whether it be the province of this science to discover merely the primary principles of substance, or also to speculate concerning the first principles from which all derive their demonstrations as, for instance, whether it is possible to affirm and deny one and the same thing, at the same time, or not, and concerning the other things of such a kind? And, if it is the province of this science to be conversant about substance, whether one may be about all, or whether there be many such in existence? and, if many, whether all are akin to each other, or it may be proper to style some of them sciences of "wisdom," and others of them, something else?

sorts or genera

And this very thing is amongst the necessary 3. Questions as points of investigation, whether it should be to the different affirmed that sensible substances exist only, of substances, or whether others also subsist in addition to and their accidents. these? and whether there is a genus singly, or a number of genera of substances, according to the opinion of those who introduce both forms and mathematical entities as things intermediate between these and sensibles? Concerning these, therefore,—as we have said,—an examination must be made; and also concerning substances, whether the speculation extend only to them, or to the essential accidents of these substances? But, in addition to these points, we might inquire in regard of sameness and diversity, and similarity and dissimilarity, and identity and contrariety, and concerning priority and subsequence, and all the rest of such things, concerning as many as the Dialecticians endeavour to

This subject is considered more at large in book III.

2 Aristotle had already discussed these points, one would suppose, with sufficient copiousness in the Topics: why, then, do these inquiries intrude into the regions of ontology? The commentators reply, that in his Logic he treats of these merely speculatively, évdóws, but here, as a metaphysician ought, really, dλnowâôs.