What is thought? One cannot grasp it — get a real hold on it — no matter how you try (in fact, the harder you try, the slipperier it is), but this is the thing Descartes based our whole being on: "I think, therefore I am." It is like a halo, hovering there in our minds, this thought thing: suspended in mid imagination like a ghost, words sometimes with half meaning, half feeling that no word is adequate for. It is so common, I think, that no one thinks about thought anymore — not really. One accepts them with the thousand other mysteries of life, the universe, and everything that allow us to be and do. The mystery of thought, though: I think it is not so deep a mystery as all that: I think because I am: I am, therefore I think.