Life is glorious when it is happy; days are carefree when they are happy; the interplay of thought and imagination is far superior to that of muscle and sinew.

All the hundreds of millions of people who, in their time, believed the Earth was flat never succeeded in unrounding it by an inch.

Any system which allows men to choose their own future will end by choosing safety and mediocrity, and in such a Reality the stars are out of reach.

A fire-eater must eat fire even if he has to kindle it himself.

Considering what human beings do and have done to human beings (and to other living things as well) ... I can never imagine what the devil people think computers can add to the horrors.

To bring about destruction by overcrowding, mass starvation, anarchy, the destruction of our most cherished values, there is no need to do anything. We need only do nothing except what comes naturally, and breed. And how easy it is to do nothing

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?"