_Socr._ Suppose, then, I beg, for the sake of argument, that we have in
our souls a waxen tablet, in one larger, in another smaller, in one of
purer wax, in another of impurer, in some of harder, and in others again
of softer, but in some of a moderate quality.
_Theæ._ I do suppose it.
_Socr._ Let us say, then, that this is a gift of Mnemosyne the mother of
the Muses; and that, whatever we wish to remember of things that we have
seen, or heard, or have ourselves thought of, we impress in this, by
placing it under our perceptions and thoughts, as if we were taking off
the impressions from rings: and that whatever is imprinted, this we
remember and know, as long as its image remains; but when it is effaced,
or can be no longer imprinted, we forget and do not know it.
_Theæ._ Be it so.
_Socr._ When, therefore, a person knows these things and considers any
of the things that he sees or hears, consider whether in this way he can
judge falsely?
_Theæ._ In what way?
_Socr._ By thinking with respect to what he knows, that they are at one
time the things that he knows, and at another the things that he does
not know. For in a former part of our discussion we made an improper
admission in admitting that this was impossible.