第五章（10）：首要实体能接受对立

Categories chapter 5 part 10

It seems most distinctive of substance that what is numerically one and the

same is able to receive contraries. In no other case could one bring forward any-thing, numerically one, which is able to receive contraries. For example, a colourwhich is numerically one and the same will not be black and white, nor will nu-merically one and the same action be bad and good; and similarly with everythingelse that is not substance. A substance, however, numerically one and the same, isable to receive contraries. For example, an individual man—one and the same—becomes pale at one time and dark at another, and hot and cold, and bad and good.

Nothing like this is to be seen in any other case, unless perhaps someone mightobject and say that statements and beliefs are like this. For the same statementseems to be both true and false. Suppose, for example, that the statement thatsomebody is sitting is true; after he has got up this same statement will be false.Similarly with beliefs. Suppose you believe truly that somebody is sitting; afterhe has got up you will believe falsely if you hold the same belief about him. How-ever, even if we were to grant this, there is still a difference in the way contrariesare received. For in the case of substances it is by themselves changing that theyare able to receive contraries. For what has become cold instead of hot, or dark in-stead of pale, or good instead of bad, has changed (has altered); similarly in othercases too it is by itself undergoing change that each thing is able to receive con-traries. Statements and beliefs, on the other hand, themselves remain completelyunchangeable in every way; it is because the actual thing changes that the contrarycomes to belong to them. For the statement that somebody is sitting remains thesame; it is because of a change in the actual thing that it comes to be true at onetime and false at another. Similarly with beliefs. Hence at least the way in which itis able to receive contraries—through a change in itself—would be distinctive ofsubstance, even if we were to grant that beliefs and statements are able to receive contraries. However, this is not true. For it is not because they themselves receiveanything that statements and beliefs are said to be able to receive contraries, butbecause of what has happened to something else. For it is because the actual thingexists or does not exist that the statement is said to be true or false, not becauseit is able itself to receive contraries. No statement, in fact, or belief is changed atall by anything. So, since nothing happens in them, they are not able to receivecontraries. A substance, on the other hand, is said to be able to receive contrariesbecause it itself receives contraries. For it receives sickness and health, and pale-ness and darkness; and because it itself receives the various things of this kind itis said to be able to receive contraries. It is, therefore, distinctive of substance thatwhat is numerically one and the same is able to receive contraries. This brings toan end our discussion of substance.