Aristotle Rhetoric 3.11.5

[5] As we have said before, metaphors should be drawn from objects which are proper to the object, but not too obvious; just as, for instance, in philosophy it needs sagacity to grasp the similarity in things that are apart. Thus Archytas said that there was no difference between an arbitrator and an altar, for the wronged betakes itself to one or the other. Similarly, if one were to say that an anchor and a pot-hook hung up were identical; for both are the same sort of thing, but they differ in this—that one is hung up above and the other below. ¹ And if one were to say the cities have been reduced to the same level, this amounts to the same in the case of things far apart—the equality of levelling in regard to superficies and resources. ²