but in the air hard; and the lyngurion is a fluid in the lynx, but is hard in the air; and the coral is soft in the sea, but hard in the air; and a tone of voice appears different produced by a syrinx, and by a flute, and different simply in the air.  Also in reference to 120 position, the same picture leaned back appears smooth, and leaned forward a little seems to have hollows and protuberances, and the necks of doves appear different in color according to the difference in inclination.  Since then all phenomena are 121 seen in relation to place, distance, and position, each of which relation makes a great difference with the idea, as we have mentioned, we shall be obliged by this Trope also to come to the suspension of judgment.  For he who wishes to give preference to certain ones of these ideas will attempt the impossible.  For if 122 he simply makes the decision without proof he will be untrustworthy.  If, however, he wishes to make use of a proof, should he say that the proof is false, he contradicts himself, but if he declares the proof to be true, proof of its proof will be demanded of him, and another proof for that, which proof also must be true, and so on to the regressus in infinitum.  It is impossible, however, to present proofs in infinitum, so 123 that one will not be able to prove that one idea is to be preferred to another.  Since then one cannot either without proof or with proof judge the ideas in question, the suspension of judgment results, and how each thing appears according to this or that position, or this or that distance, or this or that place, we perhaps are able to say, but what it really is it is impossible to declare, for the reasons which we have mentioned.

THE SIXTH TROPE.

The sixth Trope is the one based upon mixtures, according to 124 which we conclude that since no object presents itself alone, but always together with something else, it is perhaps possible to say of what nature the mixture is, of the thing itself, and of that with which it is seen, but of what sort the external object really is we shall not be able to say.  Now it is evident, I think, that nothing from without is known to us by itself, but always with something else, and that because of this fact it appears different.  The color of our skin, for example, is 125 different seen in warm air from what it is in cold, and we could not say what our color really is, only what it is when viewed under each of these conditions.  The same sound appears different in rare air from what it is in dense, and aromas are more overpowering in the warm bath and in the sun than they are in the cold air, and a body surrounded by water is light, but by air heavy.  Leaving aside, however, outer mixtures, our eyes 126 have inside of them coatings and humors.  Since then visible things are not seen without these, they will not be accurately