Commentary Aristotle Metaphysics
697. The same thing also applies regarding the question of whether things having weight are as heavy as they seem to those who are weak or to those who are strong; for it is clear that the strong judge about heavy things as they really are. But this is not the case with the weak, who find it difficult to lift a weight not only because of the heaviness of it (and this sometimes happens even with the strong), but also because of the weakness of their power, so that even less heavy things appear heavy to them.
698. The same thing again applies if the question is raised whether the truth is such as it appears to those who are asleep or to those who are awake. For the senses of those who are asleep are fettered, and thus their judgment about sensible things cannot be free like the judgment of those who are awake and whose senses are unfettered. For it has been pointed out above that it would be surprising if they should be perplexed, because it appears from their actions that they are not perplexed, and that they do not think that all of the above-mentioned judgments are equally true.
For if someone in Lybia seems in his dreams to be in Athens, or if someone in Paris seems in his dreams to be in Hungary, he does not when he awakens act in the same way that he would if he were to perceive this when he is awake. For if he were awake in Athens, he would go to the Odeon, which is a building in Athens; but he would not do this if he had merely dreamed it. It is clear, then, that he does not think that what appears to him when he is asleep and what appears when he is awake are equally true.
699. We can argue in the same way with regard to the other issues mentioned above, for even though men often raise questions about these issues, they are not in their own mind perplexed about them. Hence it is clear that their reason for holding to be true everything which appears is invalid, for they held this position because of the impossibility of deciding which of several opinions is the truer, as has been stated above.
700. Again, concerning future. Here he gives his third argument. He says that in the case of future events, as Plato points out, the opinion of a physician and that of a person who is ignorant of the art of medicine are not of equal value, that is, equally important, certain, true, or acceptable, as to the future possibility of some sick person being cured or not. For, while a physician knows the cause of health, this is unknown to someone who is ignorant of the art of medicine. It is clear, then, that the opinion which some held that all opinions are equally true is a foolish one.
701. Again, in the case. He gives his fourth argument, which runs thus. In the case of sensible objects, the judgment which a sense makes about some sensible object foreign to it and that which it makes about its proper sensible object are not of equal value, that is, equally true and acceptable.
For example, sight and taste do not make the same sort of judgment about colors and flavors, but in the case of colors the judgment of sight must be accepted, and in the case of flavors, or savors, the judgment of taste must be accepted. Hence, if sight judges a thing to be sweet and taste judges it to be bitter, taste must be accepted rather than sight.
702. And in the same way, too, the judgment which a sense makes about its proper sensible object and the one which it makes about something akin to its proper object are not of equal value.
Now those things that are said here to be akin to proper sensible objects are called common sensibles (for example, size, number, and the like), about which a sense is deceived to a greater degree than it is about its proper sensible object, although it is deceived about them to a lesser degree than it is about the sensible objects of another sense or about things that are called accidental sensible objects. Hence it is clearly foolish to say that all judgments are equally true.
703. And no one. He now gives his fifth argument. He says that no sense affirms at one instant of time that a thing is simultaneously both so and not so. For sight does not at the same moment affirm that something is white and not white or that it is two cubits and not two cubits or that it is sweet and not sweet.
But while a sense’s power of judging may seem at different times to form opposite judgments about the same thing, still from this judgment no difficulty ever arises about the sensible modification itself, but only about the subject of this modification.
For example, if we take the same subject, wine, sometimes it appears to the sense of taste sweet and sometimes not. This happens either because of some change in the sentient body, that is, in the organ, which is infected by bitter humors so that whatever it tastes does not seem sweet to it, or else because of some change in the wine itself. But the sense of taste never changes its judgment without judging sweetness itself to be such as it considered it to be in the sweet thing when it judged it to be sweet; but about sweetness itself it always makes a true affirmation, and always does this in the same way.
Hence, if the judgment of a sense is true, as these men claimed, it also follows that the nature of sweetness is necessarily such as it is; thus something will be definitely true in reality. And it also follows that both an affirmation and a negation can never be true at the same time, because a sense never affirms that something is both sweet and not sweet at the same time, as has been stated.
704. Yet all these. He gives the sixth argument. He says that, just as all of the above-mentioned theories or opinions destroy substantial predicates, as has been shown above, in a similar way they destroy all necessary predicates. For it follows that nothing could ever be predicated of anything else either substantially or necessarily. That nothing could be predicated of anything else substantially is clear from what has been stated above.
That nothing could be predicated of anything else necessarily is proved as follows. That is necessary which cannot be otherwise than it is. Therefore, if everything which is can exist in one way or in another way, as is held by those who say that contradictories and opposite opinions are true at the same time, it follows that nothing is necessary in the world.
705. And in general. Then he gives the seventh argument. He says that if everything which appears is true and a thing is true only insofar as it appears to the senses, it follows that a thing exists only insofar as it is actually being sensed. But if something exists only in this way—insofar as it is being sensed—then it follows that nothing would exist if the senses did not exist. This would follow if there were no animals or living things. But this is impossible.
706. For this can be true, that sensibles under the aspect of their sensibility do not exist. In other words, if they are considered under the aspect of sensibles actualized, they do not exist apart from the senses, for they are sensibles actualized insofar as they are present in a sense. And according to this every actualized sensible is a certain modification of the subject sensing, although this would be impossible if there were no sensory beings.
But that the sensible objects which cause this modification in a sense should not exist is impossible. This becomes clear as follows. When some subsequent thing is removed, it does not follow that a prior thing is removed. But the thing producing the modification in a sense is not the perception itself, because a perception is not the perception of itself but of something else, and this must be naturally prior to the perception just as a mover is prior to the thing which is moved. For sight does not see itself, but sees color.
707. And even if someone were to raise the objection that a sensible object and a sense are correlative, and thus naturally simultaneous, such that when one is destroyed the other is destroyed, Aristotle’s thesis is still true. For what is potentially sensible is not said to be relative to a sense because it is referred to a sense, but because the sense is referred to it, as is stated in book 5 of this work. It is clearly impossible, then, to say that some things are true because they appear to the senses, yet this is what those men maintain who claim that all appearances are true, as is evident from the foregoing statements.