10. R. First let us again and yet again ventilate this question, What is falsity? A. I wonder if there will turn out to be anything, except what is not so as it seems. R. Give heed rather, and let us first question the senses themselves. For certainly what the eyes see, is not called false, unless it have some similitude of the true. For instance, a man whom we see in sleep, is not indeed a true man, but false, by this very fact that he has the similitude of a true one. For who, seeing a dog, would have a right to say that he had dreamed of a man? Therefore too that is thereby a false dog, that it is like a true one. A. It is as thou sayest. R. And moreover, if any one waking should see a horse and think he saw a man, is he not hereby misled, that there appears to him some similitude of a man? For if nothing should appear to him except the form of a horse, he cannot think that he sees a man. A. I fully concede this. R. We call that also a false tree which we see in a picture, and a false face which is reflected from a mirror, and a false motion of buildings to men that are sailing from them, and a false break in the oar when dipped, for no other reason than the verisimilitude in all these things. A. True. R. So we make mistakes between twins, so between eggs, so between seals stamped by one ring, and other such things. A. I follow and agree to all. R. Therefore that similitude of things which pertains to the eyes, is the mother of falsity. A. I cannot deny it.

10. R. Prius quid sit falsum, etiam atque etiam ventilemus. A. Miror si quidquam aliud erit, quam quod non ita est ut videtur. R. Attende potius, et ipsos sensus prius interrogemus. Nam certe quod oculi vident, non dicitur falsum, nisi habeat aliquam similitudinem veri. Ut verbi causa, homo quem videmus in somnis, non est utique verus homo, sed falsus, eo ipso quod habet veri similitudinem. Quis enim canem videat, et recte se dicat hominem somniasse? Ergo et ille falsus canis est, ex eo quod similis vero est. A. Ita est ut dicis. R. Quid, vigilans quisque si viso equo putet se hominem videre? nonne eo fallitur quod ei appareat aliqua hominis similitudo? Nam si nihil ei appareat, nisi equi species, non potest arbitrari sese hominem videre. A. Prorsus cedo. R. Dicimus item falsam arborem quam pictam videmus, et falsam faciem quae de speculo redditur, et falsum turrium motum navigantibus, falsamque infractionem remi, ob aliud nihil nisi quod verisimilia sunt. A. Fateor. R. Ita et in geminis fallimur, ita in ovis, ita in singulis sigillis uno annulo impressis, et in caeteris talibus. A. Sequor omnino atque concedo. R. Similitudo igitur rerum quae ad oculos pertinet, mater est falsitatis. A. Negare non possum.