The Tree in the Quad and the Keys in the Washcloth
If babies know all this, what's left to learn? Quite a lot, it turns out. One classic epistemological dilemma is how we know that objects are still there even when we don't see them. As you read this, pnly a small portion of the room is actually in view. The book itself is probably occupying most of your vision. But you have no doubt that you're in a room full of other things even if you can't see them right at this moment. A pair of philosophical limericks capture the problem: