The Basic Works of Aristotle (Modern Library Classics)
Page 70
Now every term which possesses a variety of meanings includes those various meanings either owing to a mere coincidence of language, (30) or owing to a real order of derivation in the different things to which it is applied: but, though this may be taken to hold of ‘contact’ as of all such terms, it is nevertheless true that ‘contact’ in the proper sense applies only to things which have ‘position’. And ‘position’ belongs only to those things which also have a ‘place’: for in so far as we attribute ‘contact’ to the mathematical things, we must also attribute ‘place’ to them, whether they exist in separation or in some other fashion. [323a] Assuming, therefore, that ‘to touch’ is—as we have defined it in a previous work68—‘to have the extremes together’, only those things will touch one another which, being separate magnitudes and possessing position, (5) have their extremes ‘together’. And since position belongs only to those things which also have a ‘place’, while the primary differentiation of ‘place’ is ‘the above’ and ‘the below’ (and the similar pairs of opposites), all things which touch one another will have ‘weight’ or ‘lightness’—either both these qualities or one or the other of them.69 But bodies which are heavy or light are such as to ‘act’ and ‘suffer action’. Hence it is clear that those things are by nature such as to touch one another, (10) which (being separate magnitudes) have their extremes ‘together’ and are able to move, and be moved by, one another.
The manner in which the ‘mover’ moves the ‘moved’ is not always the same: on the contrary, whereas one kind of ‘mover’ can only impart motion by being itself moved, another kind can do so though remaining itself unmoved. Clearly therefore we must recognize a corresponding variety in speaking of the ‘acting’ thing too: for the ‘mover’ is said to ‘act’ (in a sense) and the ‘acting’ thing to ‘impart motion’. (15) Nevertheless there is a difference and we must draw a distinction. For not every ‘mover’ can ‘act’, if (a) the term ‘agent’ is to be used in contrast to ‘patient’ and (b) ‘patient’ is to be applied only to those things whose motion is a ‘qualitative affection’—i. e. a quality, like ‘white’ or ‘hot’, in respect to which they are ‘moved’ only in the sense that they are ‘altered’: on the contrary, (20) to ‘impart motion’ is a wider term than to ‘act’. Still, so much, at any rate, is clear: the things which are ‘such as to impart motion’, if that description be interpreted in one sense, will touch the things which are ‘such as to be moved by them’—while they will not touch them, if the description be interpreted in a different sense. But the disjunctive definition of ‘touching’ must include and distinguish (a) ‘contact in general’ as the relation between two things which, having position, are such that one is able to impart motion and the other to be moved, and (b) ‘reciprocal contact’ as the relation between two things, one able to impart motion and the other able to be moved in such a way that ‘action and passion’ are predictable of them. (25)
As a rule, no doubt, if A touches B, B touches A. For indeed practically all the ‘movers’ within our ordinary experience impart motion by being moved: in their case, what touches inevitably must, and also evidently does, touch something which reciprocally touches it. Yet, if A moves B, it is possible—as we sometimes express it—for A ‘merely to touch’ B, and that which touches need not touch a something which touches it. (30) Nevertheless it is commonly supposed that ‘touching’ must be reciprocal. The reason of this belief is that ‘movers’ which belong to the same kind as the ‘moved’ impart motion by being moved. Hence if anything imparts motion without itself being moved, it may touch the ‘moved’ and yet itself be touched by nothing—for we say sometimes that the man who grieves us ‘touches’ us, but not that we ‘touch’ him.
The account just given may serve to distinguish and define the ‘contact’ which occurs in the things of Nature. [323b] Next in order we must discuss ‘action’ and ‘passion’.
7 The traditional theories on the subject are conflicting. For (i) most thinkers are unanimous in maintaining (a) that ‘like’ is always unaffected by ‘like’, (5) because (as they argue) neither of two ‘likes’ is more apt than the other either to act or to suffer action, since all the properties which belong to the one belong identically and in the same degree to the other; and (b) that ‘unlikes’, i. e. ‘differents’, are by nature such as to act and suffer action reciprocally. For even when the smaller fire is destroyed by the greater, it suffers this effect (they say) owing to its ‘contrariety’—since the great is contrary to the small. (10) But (ii) Democritus dissented from all the other thinkers and maintained a theory peculiar to himself. He asserts that agent and patient are identical, i. e. ‘like’. It is not possible (he says) that ‘others’, i. e. ‘differents’, should suffer action from one another: on the contrary, (15) even if two things, being ‘others’, do act in some way on one another, this happens to them not qua ‘others’ but qua possessing an identical property.
Such, then, are the traditional theories, and it looks as if the statements of their advocates were in manifest conflict. But the reason of this conflict is that each group is in fact stating a part, whereas they ought to have taken a comprehensive view of the subject as a whole. For (i) if A and B are ‘like’—absolutely and in all respects without difference from one another—it is reasonable to infer that neither is in any way affected by the other. (20) Why, indeed, should either of them tend to act any more than the other? Moreover, if ‘like’ can be affected by ‘like’, a thing can also be affected by itself: and yet if that were so—if ‘like’ tended in fact to act qua ‘like’—there would be nothing indestructible or immovable, for everything would move itself. And (ii) the same consequence follows if A and B are absolutely ‘other’, i. e. in no respect identical. Whiteness could not be affected in any way by line nor linẹ by whiteness—except perhaps ‘coincidentally’, (25) viz. if the line happened to be white or black: for unless two things either are, or are composed of, ‘contraries’, neither drives the other out of its natural condition. (30) But (iii) since only those things which either involve a ‘contrariety’ or are ‘contraries’—and not any things selected at random—are such as to suffer action and to act, agent and patient must be ‘like’ (i. e. identical) in kind and yet ‘unlike’ (i. e. contrary) in species. (For it is a law of nature that body is affected by body, flavour by flavour, colour by colour, and so in general what belongs to any kind by a member of the same kind—the reason being that ‘contraries’ are in every case within a single identical kind, and it is ‘contraries’ which reciprocally act and suffer action.) [324a] Hence agent and patient must be in one sense identical, (5) but in another sense other than (i. e. ‘unlike’) one another. And since (a) patient and agent are generically identical (i. e. ‘like’) but specifically ‘unlike’, while (b) it is ‘contraries’ that exhibit this character: it is clear that ‘contraries’ and their ‘intermediates’ are such as to suffer action and to act reciprocally—for indeed it is these that constitute the entire sphere of passing-away and coming-to-be.
We can now understand why fire heats and the cold thing cools, (10) and in general why the active thing assimilates to itself the patient. For agent and patient are contrary to one another, and coming-to-be is a process into the contrary: hence the patient must change into the agent, since it is only thus that coming-to-be will be a process into the contrary. And, again, it is intelligible that the advocates of both views, although their theories are not the same, are yet in contact with the nature of the facts. (15) For sometimes we speak of the substratum as suffering action (e. g. of ‘the man’ as being healed, being warmed and chilled, and similarly in all the other cases), but at other times we say ‘what is cold is being warmed’, ‘what is sick is being healed’: and in both these ways of speaking we express the truth, since in one sense it is the ‘matter’, while in another sense it is the ‘contrary’, which suffers action. (We make the same distinction in speaking of the agent: for sometimes we say that ‘the man’, (20) but at o
ther times that ‘what is hot’, produces heat.) Now the one group of thinkers supposed that agent and patient must possess something identical, because they fastened their attention on the substratum: while the other group maintained the opposite because their attention was concentrated on the ‘contraries.’
We must conceive the same account to hold of action and passion as that which is true of ‘being moved’ and ‘imparting motion’. (25) For the ‘mover’, like the ‘agent’, has two meanings. Both (a) that which contains the originative source of the motion is thought to ‘impart motion’ (for the originative source is first amongst the causes), and also (b) that which is last, i. e. immediately next to the moved thing and to the coming-to-be. A similar distinction holds also of the agent: for we speak not only (a) of the doctor, (30) but also (b) of the wine, as healing. Now, in motion, there is nothing to prevent the first mover being unmoved (indeed, as regards some ‘first movers’ this is actually necessary) although the last mover always imparts motion by being itself moved: and, in action, there is nothing to prevent the first agent being unaffected, while the last agent only acts by suffering action itself. For (a) if agent and patient have not the same matter, (35) agent acts without being affected: thus the art of healing produces health without itself being acted upon in any way by that which is being healed. [324b] But (b) the food, in acting, is itself in some way acted upon: for, in acting, it is simultaneously heated or cooled or otherwise affected. Now the art of healing corresponds to an ‘originative source’, while the food corresponds to ‘the last’ (i. e. ‘contiguous’) mover. (5)
Those active powers, then, whose forms are not embodied in matter, are unaffected: but those whose forms are in matter are such as to be affected in acting. For we maintain that one and the same ‘matter’ is equally, so to say, the basis of either of the two opposed things—being as it were a ‘kind’;70 and that that which can be hot must be made hot, provided the heating agent is there, i. e. comes near. (10) Hence (as we have said) some of the active powers are unaffected while others are such as to be affected; and what holds of motion is true also of the active powers. For as in motion ‘the first mover’ is moved, so among the active powers ‘the first agent’ is unaffected.
The active power is a ‘cause’ in the sense of that from which the process originates: but the end, for the sake of which it takes place, (15) is not ‘active’. (That is why health is not ‘active’, except metaphorically.) For when the agent is there, the patient becomes something: but when ‘states’71 are there, the patient no longer becomes but already is—and ‘forms’ (i. e. ‘ends’) are a kind of ‘state’. As to the matter’, it (qua matter) is passive. Now fire contains ‘the hot’ embodied in matter: but a ‘hot’ separate from matter (if such a thing existed) could not suffer any action. (20) Perhaps, indeed, it is impossible that ‘the hot’ should exist in separation from matter: but if there are any entities thus separable, what we are saying would be true of them.
We have thus explained what action and passion are, what things exhibit them, why they do so, and in what manner.
8 We must go on to discuss how it is possible for action and passion to take place. (25)
Some philosophers think that the ‘last’ agent—the ‘agent’ in the strictest sense—enters in through certain pores, and so the patient suffers action. It is in this way, they assert, that we see and hear and exercise all our other senses. Moreover, according to them, things are seen through air and water and other transparent bodies, (30) because such bodies possess pores, invisible indeed owing to their minuteness, but close-set and arranged in rows: and the more transparent the body, the more frequent and serial they suppose its pores to be.
Such was the theory which some philosophers (including Empedocles) advanced in regard to the structure of certain bodies. They do not restrict it to the bodies which act and suffer action: but ‘combination’ too, they say, takes place ‘only between bodies whose pores are in reciprocal symmetry’. (35) The most systematic and consistent theory, however, and one that applied to all bodies, was advanced by Leucippus and Democritus: and, in maintaining it, they took as their starting-point what naturally comes first. [325a]
For some of the older philosophers72 thought that ‘what is’ must of necessity be ‘one’ and immovable. The void, they argue, (5) ‘is not’: but unless there is a void with a separate being of its own, ‘what is’ cannot be moved—nor again can it be ‘many’, since there is nothing to keep things apart. And in this respect,73 they insist, the view that the universe is not ‘continuous’ but ‘discretes-in-contact’74 is no better than the view that there are ‘many’ (and not ‘one’) and a void.75 For
Reasoning in this way, therefore, they were led to transcend sense-perception, and to disregard it on the ground that ‘one ought to follow the argument’: and so they assert that the universe is ‘one’ and immovable. (15) Some of them add that it is ‘infinite’, since the limit (if it had one) would be a limit against the void.
There were, then, certain thinkers who, for the reasons we have stated, enunciated views of this kind as their theory of ‘The Truth’.77 … Moreover, although these opinions appear to follow logically in a dialectical discussion, yet to believe them seems next door to madness when one considers the facts. (20) For indeed no lunatic seems to be so far out of his senses as to suppose that fire and ice are ‘one’: it is only between what is right, and what seems right from habit, that some people are mad enough to see no difference.
Leucippus, however, thought he had a theory which harmonized with sense-perception and would not abolish either coming-to-be and passing-away or motion and the multiplicity of things. (25) He made these concessions to the facts of perception: on the other hand, he conceded to the Monists that there could be no motion without a void. The result is a theory which he states as follows: ‘The void is a “not-being”, and no part of “what is” is a “not-being”; for what “is” in the strict sense of the term is an absolute plenum. This plenum, (30) however, is not “one”: on the contrary, it is a “many” infinite in number and invisible owing to the minuteness of their bulk. The “many” move in the void (for there is a void): and by coming together they produce “coming-to-be”, while by separating they produce “passing-away”. Moreover, they act and suffer action where-ever they chance to be in contact (for there they are not “one”), and they generate by being put together and becoming intertwined. From the genuinely-one, on the other hand, (35) there never could have come-to-be a multiplicity, nor from the genuinely-many a “one”: that is impossible. [325b] But (just as Empedocles and some of the other philosophers say that things suffer action through their pores, so) all “alteration” and all “passion” take place in the way that has been explained: breaking-up (i. e. passing-away) is effected by means of the void, and so too is growth—solids creeping in to fill the void places.’ (5)
Empedocles too is practically bound to adopt the same theory as Leucippus. For he must say that there are certain solids which, however, are indivisible—unless there are continuous pores all through the body. But this last alternative is impossible: for then there will be nothing solid in the body (nothing beside the pores) but all of it will be void. It is necessary, therefore, for his ‘contiguous discretes’ to be indivisible, while the intervals between them—which he calls ‘pores’—must be void. (10) But this is precisely Leucippus’s theory of action and passion.
Such, approximately, are the current explanations of the manner in which some things ‘act’ while others ‘suffer action’.
And as regards the Atomists, it is not only clear what their explanation is: it is also obvious that it follows with tolerable consistency from the assumptions they employ. (15) But there is less obvious consistency in the explanation offered by the other thinkers. It is not clear, for instance, how, on the theory of Empedocles, there is to be ‘passing-away’ as well as ‘alteration’. For the primary bodies of the Atomists—the primary constituents of which bodies are composed, and the ultimate elements into which they are dissolved—are indivisible, differing from one another only in figure. In the philosophy of Empedocles, on the other hand, it is evident that all the other bodies down to the ‘elements’ have their coming-to-be and their passing-away: but it is not clear how the ‘elements’ themselves, (20) severally in their aggregated masses, come-to-be and pass-away. Nor is it possible for Empedocles to explain how they do so, since he does not assert that Fire too78 (and similarly every one of his other ‘elements’) possesses ‘elementary constituents’ of itself.
Such an assertion would commit him to doctrines like those which Plato has set forth in the Timaeus.79 For although both Plato and Leucippus postulate elementary constituents that are indivisible and distinctively characterized by figures, (25) there is this great difference between the two theories: the ‘indivisibles’ of Leucippus (i) are solids, while those of Plato are planes, and (ii) are characterized by an infinite variety of figures, while the characterizing figures employed by Plato are limited in number. (30) Thus the ‘comings-to-be’ and the ‘dissociations’ result from the ‘indivisibles’ (a) according to Leucippus through the void and through contact (for it is at the point of contact that each of the composite bodies is divisible), but (b) according to Plato in virtue of contact alone, since he denies there is a void.