The Republic - pg. 197

"Then, if this is true," I said, "we must hold the following
about these things: education is not what the professions
of certain men assert it to be. They presumably assert
that they put into the soul knowledge that isn't in it, as
though they were putting sight into blind eyes."
"Yes, " he said, "they do indeed assert that."
"But the present argument, on the other hand," I said,
"indicates that this power is in the soul of each, and that
the instrument with which each learns - just as an eye
is not able to turn toward the light from the dark without
the whole body - must be turned around from that which
is coming into being together with the whole soul
until it is able to endure looking at that which is
and the brightest part of that which is. And we
affirm that this is the good, don't we?"
"Yes."
"There would, therefore, " I said, "be an art of this turning
around, concerned with the way in which this power can
most easily and efficiently be turned around, not an art of
producing sight in it. Rather, this art takes as given that sight
is there, but not rightly turned nor looking at what it ought to
look at, and accomplishes this object."