He studied four hours every morning, broke for lunch, then studied four hours more. He usually chose the library room with the tallest windows—the windows stretched two stories high—since he found work without sunlight depressing. (As for studying outdoors, he said it was impossible—the man who claimed he could sit beneath a palm tree undistracted was surely fooling himself.) Sometimes, in the midst of solving a particularly vexing problem, he would think so hard that he would break into a fever, taking a wet towel and pressing it to his forehead. His brain, he said, would simply overheat. Then, fever allayed, he would return to work and apply his mind once more to a multitude of dizzying equations. On occasion, his mind would stick, and the only way he could loosen it was to walk, back and forth, around the table or the perimeter of the room. He was a perambulous scholar, a man after the heart of Socrates himself.