"The most exciting moments in science are when you discover something completely new."

"I often find solace in my work, particularly when facing personal difficulties."

"You look at science (or at least talk of it) as some sort of demoralising invention of man, something apart from real life, and which must be cautiously guarded and kept separate from everyday existen…"

"You can't have a hypothesis unless you have some facts. And I haven't got any facts yet."

"The structure of tobacco mosaic virus is quite intricate, and I'm enjoying the challenge."