And if, when one asks the question simply, he adds the contradictories, he is not answering the question. For there is nothing to prevent the same thing from being both man and white and countless other things: but still if one asks whether it is true to call this a man or not our opponent must give an answer which means one thing, and not add that it is also white and large. For, besides other reasons, it is impossible to enumerate the accidents, which are infinite in number; let him, then, enumerate either all or none. Similarly, therefore, even if the same thing is a thousand times man and not-man, we must not add, in answering the question whether this is a man, that it is also at the same time not a man, unless we are bound to add also all the other accidents, all that the subject is or is not; and if we do this, we are not observing the rules of argument.

And in general those who use this argument do away with substance and essence. For they must say that all attributes are accidents, and that there is no such thing as 'being essentially man' or 'animal'. For if there is to be any such thing as 'being essentially man' this will not be 'being not-man' or 'not being man' (yet these are negations of it^[1]); for there was some one thing which it meant, and this was the substance of something. And denoting the substance of a thing means that the essence of the thing is nothing else. But if its being essentially man^[2] is to be the same as either being essentially not-man or essentially not being man, then its essence will be something else. Therefore our opponents must say that there cannot 30 be such a definition of anything, but that all attributes are accidental; for this is the distinction between substance and accident—'white' is accidental to man, because though he is white, whiteness is not his essence. But if all statements are accidental, there will be nothing primary about which they are made, if the accidental always implies predication about {{Left sidenote|1007^b a subject The predication, then, must go on ad infinitum. But this is impossible; for not even more than two terms can be combined in accidental predication. For (1) an accident is not an accident of an accident, unless it be because