U.S. has lost a battle more important and greater than Pearl Harbor.

There's no system foolproof enough to defeat a sufficiently great fool.

Had we not pursued the hydrogen bomb, there is a very real threat that we would now all be speaking Russian. I have no regrets.

Knowing he [Bob Serber] was going to the [first atom bomb] test, I asked him how he planned to deal with the danger of rattlesnakes. He said, 'I'll take along a bottle of whiskey.' … I ended by asking, 'What would you do about those possibilities [of what unknown phenomena might cause a nuclear explosion to propagate in the atmosphere]?' Bob replied, 'Take a second bottle of whiskey.'

Really exotic methods of propulsion . . . will have to be devised to get there. How it will be done, I do not know. Whether it will be done, I am not quite certain. But I would bet it can be done.

It is often claimed that knowledge multiplies so rapidly that nobody can follow it. I believe this is incorrect. At least in science it is not true. The main purpose of science is simplicity and as we understand more things, everything is becoming simpler. This, of course, goes contrary to what everyone accepts.

I think that intellectuals who end up in hell will have to read page proofs and check indexes there.