Between sessions at a physics conference, I asked a number of attendees: Who is the smartest physicist of them all?...the name mentioned most often was Witten's. He seemed to evoke a special kind of awe, as though he belonged to a category unto himself. He is often likened to Einstein; one colleague reached even further back for a comparison, suggesting that Witten possessed the greatest mathematical mind since Newton.

p. 60 - The End of Science (1996)