Michael Thorne in The Raven:
How can one learn the truth by thinking? As one learns to see a face better if one draws it.
Ludwig Wittgenstein, Zettel §255
This remark, like many of Wittgenstein’s, seems to arise from self-examination. The answer he gives suggests that he is concerned with learning just by thinking, and indeed with the particular kind of learning just by thinking that happens in philosophy (as opposed to, say, mathematics). He seems to be asking how such learning is even possible. What are we to make of his answer?
I remember being surprised when I was taught where to place the eyes when drawing a face seen from straight on. I thought I knew where the eyes went: about three-quarters of the way up. But when I really looked at a face in order to draw it, I saw that I was wrong: the eyes are halfway down the head.
This is the sort of thing one might call “learning to see a face better by drawing it.” I thought I knew how something looked, but to produce a good drawing, I had to really look—and in doing so I discovered that I didn’t know how it looked, after all.
More here.