SOCRATES: I will tell you what I suspect to be the meaning and lesson of that inscription. Let me take an illustration from sight, which I imagine to be the only one suitable to my purpose.
ALCIBIADES: What do you mean?
SOCRATES: Consider; if some one were to say to the eye, 'See thyself,' as you might say to a man, 'Know thyself,' what is the nature and meaning of this precept? Would not his meaning be:—That the eye should look at that in which it would see itself?
ALCIBIADES: Clearly.
SOCRATES: And what are the objects in looking at which we see ourselves?
ALCIBIADES: Clearly, Socrates, in looking at mirrors and the like.
SOCRATES: Very true; and is there not something of the nature of a mirror in our own eyes?
ALCIBIADES: Certainly.
SOCRATES: Did you ever observe that the face of the person looking into the eye of another is reflected as in a mirror; and in the visual organ which is over against him, and which is called the pupil, there is a sort of image of the person looking?
ALCIBIADES: That is quite true.