thing, as that which is 'many times as great' is in an indefinite relation to 1; the relation of that which exceeds to that which is exceeded is numerically quite indefinite; for number is always commensurate, but this relation may involve a 'non-commensurate number'; for that which exceeds is, in relation to that which is exceeded, so much and something more; and this something is indefinite; for it can, indifferently, be either equal or not equal to that which is exceeded. — All these relations are numerically expressed and are determinations of number, and so in another way are the equal and the like and the same, for all refer to unity. Those things are the same whose substance is one; those are like whose quality is one; those are equal whose quantity is one; and 1 is the beginning and measure of number, so that all these relations imply number, though not in the same way.
(2) The active and the passive imply an active and a passive potency and the actualization of the potencies, e.g. that which is capable of heating is related to that which is capable of being heated, because it can heat it, and, again, that which heats is related to that which is heated and that which cuts to that which is cut, because they actually do these things. But numerical relations are not actualized except in the sense which has been elsewhere[1] stated; actualizations in the sense of movement they have not. Of relations which imply potency some[2] further imply particular periods of time, e.g. that which has made is relative to that which has been made and that which will make to that which will be made. For it is in this way that a father is called father of his son; for the one has acted, and the other has been acted on in a certain way.[3] Further, some relative terms imply privation of potency, i.e. 'incapable' and terms of this sort, e.g. 'invisible'.
Relative terms which imply number or potency, therefore, are all relative because their very essence includes in its nature a reference to something else, not because something else is
