Then only the temperate person will know himself, and be able to discern what he really knows and does not know, and have the power of judging what other people likewise know and think they know, in cases where they do know, and again, what they think they know, without knowing it; everyone else will be unable. And so this is being temperate, or temperance, and knowing oneself—that one should know what one knows and what one does not know. Is that what you mean? It is, he replied. Once more then, I said, as our third offering to the Saviour, Footnote 1It was the custom at banquets to dedicate a third and final wine-offering or toast to Zeus the Saviour. Cf. Pind. I. 5 init. let us consider afresh, in the first place, whether such a thing as this is possible or not—to know that one knows, and does not know, what one knows and what one does not know; and secondly, if this is perfectly possible, what benefit we get by knowing it. We must indeed consider, he said. Come then, I said, Critias, consider if you can show yourself any more resourceful than I am; for I am at a loss. Shall I explain to you in what way? By all means, he replied. Well, I said, what all this comes to, if your last statement was correct, is merely that there is one science which is precisely a science of itself and of the other sciences, and moreover is a science of the lack of science at the same time. Certainly. Then mark what a strange statement it is that we are attempting to make, my friend: for if you will consider it as applied to other cases, you will surely see—so I believe—its impossibility. How so? In what cases? In the following: ask yourself if you think there is a sort of vision which is not the vision of things that we see in the ordinary way, but a vision of itself and of the other sorts of vision, and of the lack of vision likewise; which, while being vision, sees no color, but only itself and the other sorts of vision. Do you think there is any such? Upon my word, I do not. And what do you say to a sort of hearing which hears not a single sound, but hears itself and the other sorts of hearing and lack of hearing? I reject that also. Then take all the senses together as a whole, and consider if you think there is any sense of the senses and of itself, but insensible of any of the things of which the other senses are sensible. I do not. Now, do you think there is any desire which is the desire, not of any pleasure, but of itself and of the other desires ? No, indeed.Nor, again, is there a wish, I imagine, that wishes no good, but wishes itself and the other wishes. Quite so; there is not. And would you say there is any love of such a sort that it is actually a love of no beauty, but of itself and of the other loves? Not I, he replied.