“Naturally, there's got to be a limit for I don't expect to live forever, but I do intend to hang on as long as possible.”

“Does everyone just believe what he wants to?""As long as possible. Sometimes longer.""What about you?""You mean, am I human? Certainly. I don't believe I'm really old. I believe I'm quite attractive. I believe you seek out my company because you think I'm charming - even when you insist on turning the conversation to physics.”

“Once, when a religionist denounced me in unmeasured terms, I sent him a card saying, "I am sure you believe that I will go to hell when I die, and that once there I will suffer all the pains and tortures the sadistic ingenuity of your deity can devise and that this torture will continue forever. Isn't that enough for you? Do you have to call me bad names in addition?”

“Despite all that education and experience can do, I retain a certain level of unsophistication that I cannot eradicate and that my friends find amusing. In fact, I think I sometimes detect conspiratorial plottings among my friends to protect me against my own lack of sophistication. I don't mind. I suspect that I am never quite as unsophisticated as they think I am, but I don't mind.”

“I am an atheist, out and out. It took me a long time to say it. I've been an atheist for years and years, but somehow I felt it was intellectually unrespectable to say one was an atheist, because it assumed knowledge that one didn't have. Somehow, it was better to say one was a humanist or an agnostic. I finally decided that I'm a creature of emotion as well as of reason. Emotionally, I am an atheist. I don't have the evidence to prove that God doesn't exist, but I so strongly suspect he doesn't that I don't want to waste my time.”

“You see, proteins, as I probably needn't tell you, are immensely complicated groupings of amino acids and certain other specialized compounds, arranged in intricate three-dimensional patterns that are as unstable as sunbeams on a cloudy day. It is this instability that is life, since it is forever changing its position in an effort to maintain its identity--in the manner of a long rod balanced on an acrobat's nose.”

“I suppose there's no way of putting the mushroom cloud back into that nice, shiny uranium sphere.”