Metaphysics

​But there are some, both among those who are convinced of these things and among those who only repeat these arguments, who are in difficulty; for they ask who is the one to judge the healthy person, and on the whole, who will judge correctly about each matter. Such difficulties are similar to doubting whether we are now asleep or awake; and all such difficulties have the same force. For these people demand that there be a reason for everything; they seek a starting-point, and they want to obtain this by demonstration—since that they are not actually convinced is clear from their actions. But as we said, this is their affection: they seek a reason for things for which there is no reason; for the starting-point of demonstration is not a demonstration. Now these indeed might easily be convinced of this (for it is not difficult to grasp); but those who seek only force in argument seek the impossible, for they demand to state contraries, immediately stating contraries themselves. But if not all things are relative, but some are also independent in themselves, then not everything that appears could be true; for that which appears is what appears to someone. So he who says that all appearances are true makes all things that are relative. Therefore, those who seek force in argument, and at the same time claim to sustain an argument, must guard themselves by this: that it is not simply the appearance that exists, but the appearance to whom it appears, and when it appears, and in what way, and how. And if they sustain an argument, but do not sustain it in this way, it will quickly happen that they contradict themselves. For it is possible that the same thing appears to be honey to the sight, but not to the taste, and since we have two eyes, not the same things appear to each of the two sights, if they are unlike. Since, indeed, to those who on account of the aforementioned causes assert that what appears is true, and for this reason that all things are likewise false and true—for neither do the same things appear to all, nor always the same things to the same person, but often contrary things at the same time (for touch says there are two things when the fingers are crossed, but sight says there is one)—yet not, surely, to the same sense and in the same respect and in the same way and at the same time; so that this would be true. But perhaps for this reason those who speak not from difficulty but for the sake of argument must say that this is not simply true, but true to this person. And as indeed has been said before, they must make everything relative, both to opinion and to sensation, so that nothing has come to be or will be without someone having first opined it. But if anything has come to be or will be, it is clear that not all things could be relative to opinion. Furthermore, if a thing is one, it is relative to one thing or to a definite thing; and if the same thing is both a half and equal, yet the equal is surely not relative to the double. If indeed, in relation to that which opines, man and that which is opined are the same, that which opines will not be man, but that which is opined. And if each thing is to be relative to that which opines, that which opines will be relative to things infinite in species. That, then, the most secure opinion of all is that contradictory assertions are not true at the same time, and what happens to those who speak thus, and why they speak thus, let so much be said. And since it is impossible for contradiction to be true at the same time of the same subject, it is clear that contraries also cannot belong to the same subject at the same time; for of contraries, one is no less a privation, and indeed a privation of substance; and privation is a negation from some definite genus. If, then, it is impossible to affirm and deny truly at the same time, it is also impossible for contraries to belong to the same subject at the same time, unless both belong in a certain respect, or one in a certain respect and the other absolutely.