We are reaching the stage where the problems we must solve are going to become insoluble without computers. I do not fear computers, I fear the lack of them.

The laws of history are as absolute as the laws of physics, and if the probabilities of error are greater, it is only because history does not deal with as many humans as physics does atoms, so that individual variations count for more.

The dangers that face the world can, every one of them, be traced back to science. The salvations that may save the world will, every one of them, be traced back to science.

Humanity is cutting down its forests, apparently oblivious to the fact that we may not be able to live without them.

Why continue? Because we must. Because we have the call. Because it is nobler to fight for rationality without winning than to give up in the face of continued defeats. Because whatever true progress humanity makes is through the rationality of the occasional individual and because any one individual we may win for the cause may do more for humanity than a hundred thousand who hug their superstitions to their breast.

Experimentation is the least arrogant method of gaining knowledge. The experimenter humbly asks a question of nature.

To insult someone we call him 'bestial. For deliberate cruelty and nature, 'human' might be the greater insult.