It is curious how often this habit of movement goes with thinking. Montaigne says: "Every place of retirement requires a Walk. My thoughts sleep if I sit still; my Fancy does not go by itself, as it goes when my Legs move it." What Montaigne seems to mean is that we love rhythm. Body and mind must move together in harmony. So it is with the Mohammedan over the Koran, and the Rabbi over the Talmud. Jews sway at prayer for the same reason. Movement of the body is not a mere mannerism; it is part of the emotion, like the instrumental accompaniment to a song.