Works of Aristotle, Vol. I (Aristotelis Opera)

...to receive contraries at the same time, such as in the case of substance; for while it seems capable of receiving contraries, it is not the case that it is simultaneously sick and healthy. Nor is it simultaneously white and black. Nor is there anything else that receives contraries at the same time. And it happens that they themselves are contrary to themselves. For if "great" is contrary to "small," and the same thing is at once great and small, it would be contrary to itself. But it is among the impossibilities for something to be contrary to itself; therefore, "great" is not contrary to "small," nor is "much" to "little." Thus, even if one does not call these relative things but rather quantities, they will have no contrary.

It is especially in the case of place that the contrariety of quantity seems to exist. For they posit "up" as contrary to "down," calling the region toward the center "down," because the distance from the center to the extremities of the cosmos is the greatest. And they seem to derive the definition of other contraries from these; for those things in the same genus that are most distant from one another are defined as contraries.

Quantity does not seem to admit of "more" or "less," such as "two-cubit"; for one thing is not more two-cubit than another. Nor is this true in the case of number, such as three being more three than five, nor five more five than three. Nor is one time said to be more a time than another. Nor is "more" or "less" used regarding any of the things mentioned at all. Thus, quantity does not admit of "more" and "less."

It is most especially a property of quantity to be called "equal" and "unequal." For each of the aforementioned quantities is called equal and unequal; for instance, a body is called equal and unequal, and time is called equal and unequal. In the same way, each of the others mentioned is called equal and unequal. But for the remaining things that are not quantities, one would not easily think they are called equal or unequal; for instance, a disposition is not easily called equal or unequal, but rather "similar," and "white" is not easily called equal or unequal, but "similar." Thus, it would be most proper to quantity to be called equal and unequal.

7 Things are called relative pros ti relative/related to something when they are said to be what they are in relation to other things, or in any other way in relation to something else. For example, "the greater" is said to be what it is in relation to something else; for it is called greater than something. And "the double" is said to be what it is in relation to something else;

for it is called double of something. The same applies to other such things. Also, such things as a state, a disposition, perception, knowledge, and position are relative things. For all these things mentioned are said to be what they are in relation to others and not something else; for a state is called the state of something, knowledge is the knowledge of something, position is the position of something, and the same applies to others. Therefore, things are relative when they are said to be what they are in relation to others, or in any other way in relation to something else; for instance, a mountain is called great in relation to something else; for the mountain is called great relative to something. And "the similar" is called similar to something, and other such things are similarly called relative. Furthermore, reclining, standing, and sitting are certain positions, and position is among relative things. But to be reclined, to stand, or to be seated are not themselves positions, but are called by names derived from the aforementioned positions.

Contrariety also exists among relative things, for instance, vice is contrary to virtue, both being relative things, and ignorance to knowledge. But contrariety does not belong to all relative things; for there is no contrary to "double," nor to "triple," nor to any such thing.

It also seems that relative things admit of "more" and "less"; for "similar" and "dissimilar" are called so more or less, and "equal" and "unequal" are called so more or less, each of them being relative; for the similar is called similar to something and the dissimilar is called dissimilar to something. However, not all relative things admit of "more" and "less"; for "double" is not called more or less double, nor is anything of that sort.

All relative things are spoken of in relation to reciprocals things that correlate, like master and slave. For example, the slave is called the slave of the master, and the master is called the master of the slave; and the double is the double of the half, and the half is the half of the double; and the greater is the greater of the lesser, and the lesser is the lesser of the greater. The same applies to others, except that sometimes the case grammatical case will differ in the expression; for instance, knowledge is called the knowledge of the knowable, and the knowable is called knowable by knowledge; and perception is the perception of the perceptible, and the perceptible is perceptible by perception. Nevertheless, sometimes what seems to be a reciprocal does not reciprocate if the one who assigns it fails to assign it properly to that in relation to which it is said; for instance, if "wing" is assigned to "bird," the bird does not reciprocate to the wing. For it is not properly assigned...