" The thing that strikes me is that I’ve cut myself off a really different version of this, then, because I thought I had ended this problem. And it just came around from behind much worse, Because the way I was always phrasing it was in terms of a posteriori knowledge - that is, empirical knowledge, which is all sophisticated versions of, you kno, ‘Is this chair real?’ It’s that sort of simplistic philosophical thing, it’s sort of a kind of solipsism. "

― Philip K. Dick