^ Firom hifl solution of the question as to the existence in a subject of a capacity for contraries, Aiistotle now decides a point connected with the unity of external objects in relation to the percipient.
* This is the reading in Didot's edition, and Is more clear than that is the IieipHic text.
224 THE HETAPHTBIOB OF ARIffrOTLB. [BOOK Til.
evident that to persons treating the subject in such a way ai they have been accustomed to frame their definitions and assertions, it is not possible to adduce a reason of this and solve the matter in doubt.
2 The real so- "^^^ ^^ ^^® ^^^^ stands as WO Say, namely, lutionofihia that One thing, indeed, is matter, but another the difference " ^o^*"^* — ^^ud, again, that one thing subsists in ear between capa- pacitv, but another in eners^y, — no longer would the matter under investigation seem a sub- ject of doubt, for this doubt is the same as if the round brass were the definition of a garment. For this name would be a sign of the definition; wherefore, the object of investiga- tion is what the cause is that the circular and the brass are one. No longer, however, does the doubt appear to remain, because the ope is matter, but the other form. What, then, is the cause of this, namely, that what subsists in capacity should subsist in energy beside the producing cause — I mean, in the case of whatsoever things there is generation 1 for there is no other cause of the sphere that subsists in capacity subsisting as a sphere in energy, but this was the essence in each thing. And as regards matter, there is one kind that is intelligible, and another that is cognisant by the senses; and as regards vdefiuition, one sort, indeed, is invariably matter, and another is energy, as a circle is a plain figure. As many things, how- ever, as do not involve matter, either intelligible or sensible, forthwith is it possible that each of these be one certain par- ticular thing, as tliat which is a certain particular thing is this particular thing as well as quality and quantity; wherefore, also, there does not inhere in definitions either entity or unity, and the essence or very nature of a thing is forthwith a certain unity, as also a certain entity; wherefore, also, there is not any difierent cause for any of these being one, or of there being a certain entity in them, for immediately doth each constitute a certain entity and a certain unity; yet they are not inherent in entity or unity as in the genus ^ of these, nor have they a subsistence as though they were separable from singulars.
3. An attempt- And, ou accouut of this aforesaid doubt, some u fr(°m"h2 °^ philosophers maintain that participation, to wit, •kenomenon of is the cause j and what the cause of the participa- ' y€p§i: other MSS. r«ad y€v(<r€u CH.VI.] THIS SUBJECT FUBTHEB DISOUSSID. 225 tiou ifl, and what the participation itself is, they paTtieii4.ti<m, are in doubt; but some assign the intercourse M^^«f«»- of the soul as the cause, just as Ljcophron,^ who says that science is the union of the act of scientific knowledge and of the soul: but others affirm that the principle of vitality consists in the composition or conjunction of soul with body. Indeed, the same reasoning holds good as regards all things; for also the being in sound health will be either the union, or conjunction, or composition of soul with health. And for the brass to be a triangle will be a composition of brass and of triangle, and for a thing to be white will be a composition of superficies and whiteness; and a cause of their speaking in this way is because they are searching for the uniting principle and dif- ference of capacity and actuality. But, as has been said, both the ultimate matter and the form are the same; and the one subsists in capacity, but the other in actuality. Wherefore, the investigation of what is the cause of unity is similar to the inquiry into the cause of a thing being one; for everything is one particular thing subsisting both partly in capacity and partly in energy, in a certain respect, as one thing. Wherefore, there is no other cause, except there be something that can be shown to subsist as a cause imparting motion from potentiality into energy. Now, whatever things do not involve matter, all of these are simply some certain particular thing.
* Lycophron. It does not appear who this Lycophron was; the oommentators merely say of him that he was a sophist, pr&bably a contemporary of Aristotle. He certainly was not the graat poet cf Ihatname.
BOOK VIIL* CHAPTER L 1. Hpw meta- 'CONCERNING substoDce, then — I mean, oonoem- l^lSnc^o? ^^8 ^^*^ which is primarily entity, and to which ail the "ens,'* is the rest of the categories of entity are referred — capacity, dy- WO have declared our sentiments. For according •^M*v. to the definition of substance ai'e denominated the other entities, viz. both quantity, and quality, and the rest of the things that are predicated in this way; for all such will involve the definition of subistance, as we have as- serted in our earliest dissertations.^ But since entity is denominated partly as quiddity, or quality, or quantity, but partly according to capacity and actuality, and according to work, let us frame certain distinctions and definitions as regards both capacity and actuality; and, in the first in- stance, as regards that capacity, or potentiality, which is spoken of as such with especial precision: not, to be sure, that this is of service towards the advancement of our present design, for potentiality and actuality extend further than things merely predicated according to motion. But when we have spoken our opinions concerning this in our definitions, as regards energy, we shall make matters plain concerning the other points likewise.
2. Several That, indeed, therefore, potentiality is predi- SSity" OT^?i^°' *^*®^ ^^ many ways, and that the possession of city, enume- potentiality is expressed in many ways, has been rated. settled by us elsewhere.^ But as many of these as are styled potentialities equivocally may be omitted; for ' In the eighth book — ninth according to some — Aristotle considers the subject of capacity and energy with more minuteness. It is well worthy of study, not merely for the distinctions which are found drawn ill it, but also for the admirable classification of capacities, or poten- tialities, which it contains.
^ Vide book VI. chap. i.
* In the fourth bool^ — his book of metaphysical definitions, — where the term diiyams, in its various significations^ is folly explained. Vid4 chap. xii. of that book.
OH. l] ontology treats about poientiality. 227 8ome capacities, or potentialities, are deuominated capacities by reason of a certain similarity (as in geometry we speak of potentiality in this way), and things that are potential and impotential we call such in regard of their being, in a certain respect, endued with such a capacity, or not being so. As many potentialities, however, as are referred to the same form or species are all certain first principles, and are pre- dicated in reference to one primary potentiality,^ which is a first principle of change in another body, so far forth as it is another. For there is a capacity, on the one hand, of being passive, which, in the actual subject of passion, constitutes a first principle of a passive state through the intervention of another body, so fiir forth as it is another. There is, on the other handj the habit of impassivity, such as tends towards a condition which is worse, and the habit of corruption, which arises from the instrumentality of another body, so far fortii as it is another — I mean, a first principle capable of bringing about a change. For in all these definitions is inherent the definition of the primary potentiality just mentioned. Auc" again, these potentialities are styled either those of action merely, or passion, or subsistence in an excellent manner.
Wherefore, also, in the definitions of these are inherent, in a manner, the definitions of the former potentialities.
It is, therefore, evident that there is, in a 3. inferences certain respect, one potentiality of action and fh?s^"num?ra- passion, — for a thing that is potential is such in tion of poten- I'egard of itself having the potentiality of passive- *^"*®*- ness, and in regard of another thing having it by reason of this, — and, in another respect, there is a different potenti- ality. For one kind of potentiality resides in the patient; for, on account of its having a certain first principle, and on account of matter,^ also, being a certain first principle, the subject of the passion is passive, and one thing uudergces a change by reason of another; for that which is fat is combustible also: but that which yields in this manner * These words are worthy of attention; for by thus making every capacity in its action relative to the operation of a certain other capa* city, we ultimately arrive at the primary capacity; and this, according to principles already established, presupposes a something beyond capacity, an activity, the absolute iydtfjuot the first cause.
q2 is a thing that is bruised; and in like manner, also^ is it with other things. But another kind of potentiality resides in the agent, as the hot, and the capacity of house-building, are involved severally, tiie former in that which is capable of making a thing warm, and the latter in a person who va qualified to build a house. Wherefore, as &r forth as a thing is naturally connected with itself it in no wise under- goes a passive state itself by reason of its own agency, for it is one thing, and not anything else.
4. What impo- -^"^ impoteutiality, and that which is impo;- tentiaiity is, teutial (uow, such is Contrary to potentiality), is udy»a/A«a. privatiou. Wherefore, every potentiality belongs to the same, and subsists according U> the same subject with im- potentiality. Privation,^ however, is predicated in many ways; for privation is to be found where a thing does not possess something else, and, though 6tted by nature for the possession of such, may yet not have it either entirely or when it is fitted by nature: and we say either, after this manner, that it is privation, for instance, altogether so, or yet even in some certain respect or other. And, in the case of some things, if being by nature adapted to possess a thing, they may not yet have such by reason of violence, we say that these are subjects of privation in this respect.
CHAPTER II.
I As to poten- SiKCE, however, such first principles of poten- tialities, some tiality are inherent partly in things that are JJJ'n^f con!" inanimate, and partly in things that are animato nected'with and Contained in soul, and in that portion of the "**®"* soul which possesses reason, it is evident that also of potentialities some will be devoid of reason, whereas others will be accompanied with reason. Wherefore, all the arts, even such as are constructive,' as well as the sciences, are potentialities; for they constitute first principles which are causes of clmnge in another subject, so far forth as it is another. And all those potentialities, indeed, that ara ' The term privation, artprio'is, has been already defined in book lY shap. xxiu ' Some copies read, km iroivriKa* MariiMai, CSLIL] RATIONAL AND tBILVTIONAL OAFAOlTIEg. 229 accompanied, or involve any connexion with reason, are pro- ductive of contraries; each of those, however, that is devoid of reason is alone productive of one result: as, for instance, that which is hot is productive of the promotion of heat merely, and the medicinal art of disease and health.
And a cause of this is the following, that 2. Difference scientific knowledge is reason, and the same {"ve^^wenTof reason makes manifest the result produced and these two its privation, though not after the same manner; teiSiamy ^' and in one way is this reason that which creates counted for. this knowledge for both,^ yet in another it affords greatef knowledge of the thing in existence than of its privation. Wherefore, it is requisite that such sciences as these should involve a knowledge of contraries; but that of the one it should be thus essentially, and of the other not essentially - for also reason is a knowledge of the one essentially, but oi the other, aft^er a certain manner, according to accident, for by negation and ablation it makes manifest the contraiy; for primary privation is that which is contrary, and this is an ablation of the other. Since, however, contraries are not inherent in the same thing — now, science is a capacity in respect of the possession of reason,^ and the soul also pos- sesses a first principle of motion — hence the healthy or salubrious produces health only, and that which is capable of promoting heat — warmth, and of promoting cold — chilli- ness; but the scientific person produces l)oth. For of both, no doubt, has reason a knowledge, but not in the same manner; and this reason subsists in a soul which possesses a first principle of motion. Wherefore, soul will move both from the same first principle, having effected coherence towards the same thing; wherefore, the things which are potential, or endowed with capacity according to reason, produce contraries to the productions of that which is poten- tial without reason, for. one first principle is comprised in reason. But it is evident that also upon the ^ ^her^ I power of action and^ passion in an excellent notneceuarUy * I have followed Taylor^s paraphrastic rendering of this passage.
' What Aristotle means is this, — ^that science presupposes in man a scientific capacity, and that this is to be found in the rational soul, which contains within itself the efficient cause of man*s pursuit a5M knowledge.
230 THE ITETAPHTSICS OF ARTSTOTLK. JIlOOKVlll ioToived in the manner there follows the power merely of action i6^,tf ^^ ^^ passion: but in this latter the former ia not invariablj to be found; for he that acts well must needs also be an agent, but where a person only is an agent it is not necessary, also^ that he should act well.
CHAPTER IILi 1. False notions BuT there are some who say — ^for instance^ whoo*iM^fr^° those of the Megaric school — ^that where there energy being a is energy, there only is there potentiality, or d?uo"fbr po? capacity, but that where there is no energy, there tentiaiity. ig no potentiality; for example, that the person who does not actually build has not the capacity of buildings but that he has the capacity of building when he actually builds, and that it is in like manner, also, with other thingsi Now, the absurdities which ensue with these speculators it is not difficult to discover. For it is evident that neither will he be a builder if he does not actually build; for the being of a builder consists in the possession of the capacity of building; and in like manner, lUso, it is the case with the rest of the arts. If, therefore, it is impossible for one to possess arts of this kind, if he has not at any time received instruc-' tion in them, and acquired them, and not to be in the posses- sion of them, unless at some time or other he lose them, (for one may do so either through forg^fulness, or a certain affection, or time; for as to the thing itself, that, at any rate^ has not fallen into decay, for it -is in existence always;) this being the case when there may be a cessation of operation on the part of such a one, he will not have in possession the art, and how will he again forthwith proceed to build in resuming the art which he had lost 1 ^ Aristotle, by what goes before, is led to attack the Megarian philo* Bopbers, who confounded everything with " being," and, therefore, po- tentiality with energy. The rallying point of the Megarics. was the school established at Megara by Euclid, a native of ihe place; and Aristotle, no doubt, has his eye fixed principally on Euclid, for the latter was a most vehement opponent of the dogmatism of the Peri* Eitetics. Vide Tenneman, p. 98, translated in " Bohn's Philological ibrary."
OB. ni.] THB MBOABTA^ THEOBT DF OAPAOITT 231 And in like manner will it be the case, also, s.thisMegari* with things that are inanimate; * for there f^fTheS^^^or will be neither cold, nor hot, nor sweet, nor, in Proiagmas re- short, anythmg cognisable by sense, when such p^l^^ is not an object of sensation. Wherefore, it will ivity of our happen with these philosophers that they should '*""* °"** put forward the same theory with Protagoras. But, unques* tionably, neither will a man possess any sense imless he per-» ceives or energizes. If, therefore, that animal is blind which does not possess the power of vision, though naturally adapted to see, and when it is naturally adapted to see, and, further, as it is thus naturally adapted, in such a case the same individuals oftentimes during the same day will be blind, and in like manner deaf Further, if that which is impoten- tial be that which has been deprived of capacity, that which has not been generated, to be generated will be a thing that is impossible; but one who says that what is devoid of a capacity of being generated, either actually exists, or will do so, shall affirm what is &lse j for this would signify what is impo- tentiaL Wherefore, these assertions overturn both the ex- istence of motion ^ and of generation; for that which stands will always stand, and that which sits will always remain in a sitting posture; for a man wiU not rise up if he be sitting down, for it will be impossible for that to rise up which would not possess the capability, at least, of rising up.
I^ therefore, it may not be possible to afi&rm 3 ^^^^^ ^^^^ these things, it is evident that potentiality and neous views energy are something different from each other; JhTlifferenw those theories, however, make potentiality and 2^?®^"'**^*^^ energy to be the same: and thus it is not a from each small thing which they are seeking to over- ®'^®'* turn. Wherefore, it happens that a thing admits of being, and yet may not be, and that a thing admits of not being, and yet may be. In like manner, also, is it with the rest of the categories: that which is endued with the capacity of ' Protagoras founded his scepticism on the pure relativity of our sensations, and Bishop Berkeley endeavoured to build the reality of God's existence on the same foundation. What a different philosophy resulted from the same suggesting cause to the mind of the impious and daring sceptic, and to that of the humble and confiding Christian!
' And, iherefore, such theories, when pushed forward to their legi^ mate conviquences, must end in atheism.
232 THB MUTAPHT8ICB OF ARISTOTLE. [BOOK TIH.
walking yet may not walk, and that which does not walk may yet be able to walk. This, however, is a thing that is potential, in which, when the energy is present of that of which it is said to have the capacity, there will not be in existence anything that is devoid of potentiality. Now, I mean, {or instance, if one is able to sit, and it so happens that such a one sits, if the sitting posture will have an exist- ence in the case of such a one, nothing impossible or impo- tential will ensue. And if anything may be moved, or may impart motion, or remain at rest, or impede a body in its course, or be in existence, or be generated, or not be in existence, or not be generated, the case will be similar.
4 Theoririn ^^^ *^® name, energy,* which is combined of the name with actuality, and tends towards other things, olf S SStSre. ^^^ proceeded forth from motions principally; for motion in an eminent sense appears to constitute the energy of a thing. Wherefore, also, to nonentities they do not attribute the having motion imparted to them, but certain other categories: as, for instance, things which are nonentities are intelligible and desirable objects, but are not in motion. And this is the case because nonentities in energy will, how- ever, subsist in energy; for of nonentities some are nonentities in capacity, but yet have no existence because they do not exist actually.
CHAPTER IV.2 1. Potentiality Now, if the potential be that which it has oondit^orto"^ been declared to be, upon which energy is conse- energy. qucutial, it is evident that it is not possible that it be true to say that this particular thing is endued with a capability of being, but yet will not exist; so that, on this sup- position, what things impotential are would elude our search. Now, I say, for instance, this is just as if any one afi&rm it to * Because, if we view energy as it were in a state of rest after the end to which it tends has been brought about, this presupposes that it has accomplished this transition through the intervention of motion; or regarding energy in this very state of transition towards an end, — CIS TO t4\o5, — we must regard it as motion itself.
' Aristotle now considers the converse of the proposition ascribed Uf the Megarics in the last chapter.
OIL IV.] THE OONYEBSB OF THIS THEORY. 233 be possible that the diameter of a square be commensurate with its side, although this commensurability will never be established; not reckoning that it is a thing that is impossible, because nothing hinders anything that is potential, in regard of existence and of generation,^ from not being, nor being likely to exist. But that follows necessarily from the points laid down, if, also, we should suppose a thing may be, or may be generated, which is not in existence, I admit, but yet is a thing that is endued with the capacity of being; because there will be in such a supposition as this nothing that is impossible: but, at any rate, it will be admitted that this result will ensue; for, allowing the commensurability of the diameter, the inference must follow that even are equal to odd numbers, which is an impossibility.^ For what is false is not the same also with that which is impotential; for that you now are in a standing position is £alse, to be sure, but is not a thing that is impossible.^ And at the same time, also, is it evident that, ^ niustration upon the supposition of the existence of A, B of this bv must needs exist likewise; and if A exist sb ^taSoisf a thing that is potential in regard of being, it follows that also B must needs be a thing that is potential in regard of being; for if there be no necessity for its being a thing potential in regard of being, nothing hinders that which is a thing possible to be from not being at all. Now, let A be a thing that is possible to be. Therefore, since A is a thing possible to be, if A be admitted as existing, nothing impossible to be would actually ensue. However, B, at any rate, must necessarily exist; but this was impossible. Grant, therefore, that it is impossible. If, then, it were impossible for B ^ to exist necessanly, it is necessary that it should be impossible for A to exist But then A was possible, there- fore will B be BO likewise. If, then, A be possible, B also "* The commentatorB say that Aristotle here glances at Plato for an opinion of his as regards the generation, and, therefore, the corruptibility of the celestial spheres. This would directly clash with the notions oi the Stagyrite; mde De Coelo, book L chap. z.
' This is Taylor^s paraphrastic rendering of the text Vide note, p. 109.
' This distinction between these two significations of the word f^tv^os is most worthy of our attention.
* The Leipsic edition has A here inftead of B, which quite destroyi the link in this chain of reasoniiifr 234 THB 1IETAPHY8I0S OF ARISTOTLE. [fiOOK Ylll.
will be possible, if they subsist in such a way as that in con* sequence of the existence of A, B necessarily exiits also. J^ therefore, on the supposition that the things signified by A B subsist in this manner, it may not be a thing possible for this to take place in reference to B in this way, neither will A B subsist in the manner that has been laid down; and if^ on the supposition of the possibility of the existence of A, it is necessary that B also i^ould exist as a thing that is pos* Bible to be, supposing, then, A to exist, it is necessary also that B exist. For that it is possible from necessity for B to exist, if it be possible for A to exist, signifies as follows, that if A exists, and when it exists, and as far as it is a thing that is possible to oxist^ that then, and in this way also, that is necessary in r^ard of the existence of B.
CHAPTER V.