Seite - 671 - in The Complete Aristotle

one, reciprocal action and passion could not have occurred’. The hot thing, e.g. would not be cooled and the cold thing in turn be warmed: for heat and cold do not change reciprocally into one another, but what changes (it is clear) is the substratum. Hence, whenever there is action and passion between two things, that which underlies them must be a single something. No doubt, it is not true to say that all things are of this character: but it is true of all things between which there is reciprocal action and passion. But if we must investigate ‘action-passion’ and ‘combination’, we must also investigate ‘contact’. For action and passion (in the proper sense of the terms) can only occur between things which are such as to touch one another; nor can things enter into combination at all unless they have come into a certain kind of contact. Hence we must give a definite account of these three things—of ‘contact’, ‘combination’, and ‘acting’. Let us start as follows. All things which admit of ‘combination’ must be capable of reciprocal contact: and the same is true of any two things, of which one ‘acts’ and the other ‘suffers action’ in the proper sense of the terms. For this reason we must treat of ‘contact’ first. every term which possesses a variety of meaning includes those various meanings either owing to a mere coincidence of language, 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. Assuming, therefore, that ‘to touch’ is-as we have defined it in a previous work’-’to have the extremes together’, only those things will touch one another which, being separate magnitudes and possessing position, 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. 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, 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’ 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 671