However, to abridge the controversy, consider, I pray you, within what narrow bounds you are confined. There are four principles which conduct you to the conclusion that there is nothing which can be known, or perceived, or comprehended;—and it is about this that the whole dispute is. The first principle is, that some perceptions are false; the second, that such cannot be perceived; the third, that of perceptions between which there is no difference, it is not possible that some of them can be perceived and that others cannot; the fourth, that there is no true perception proceeding from the senses, to which there is not some other perception opposed which in no respect differs from it, and which cannot be perceived. Now of these four principles, the second and third are admitted by every one. Epicurus does not admit the first, but you, with whom we are now arguing, admit that one too,—the whole contest is about the fourth. The man, then, who saw Publius Servilius Geminus, if he thought that he saw Quintus, fell into a perception of that kind that could not be perceived; because what was true was distinguished by no characteristic mark from what was false: and if this distinctive mark were taken away, what characteristic of the same kind could he have by which to recognise Caius Cotta, who was twice consul with Geminus, which could not possibly be false? You say that such a likeness as that is not in the nature of things. You fight the question vigorously, but you are fighting a peaceably disposed adversary. Grant, then, that it is not; at all events, it is possible that it should seem to be so; therefore it will deceive the senses. And if one likeness deceives them, it will have made everything doubtful; for when that judgment is once taken away by which alone things can be known, then, even if the person whom you see, be really the person whom he appears to you to be, still you will not judge by that characteristic which you say you ought, being of such a character that one of the same kind cannot be false. If, therefore, it is possible that Publius Geminus may appear to you to be Quintus, what certainty have you that he may not appear to you to be Cotta though he is not, since some things do appear to you to be what they are not? You say that everything has its own peculiar genus; that there is nothing the same as something else. That is a stoic doctrine, and one not very credible, for they say that there is not a single hair or a single grain in every respect like another hair or grain. These things could all be refuted, but I do not wish to be contentious; for it has nothing in the world to do with the question whether the things which are seen do not differ at all in any part, or whether they cannot be distinguished from another even though they do differ. But, granting that there cannot be such a likeness between men, can there not be such between statues? Tell me, could not Lysippus,