Visualize yourself confronted with the task of killing, one after the other, a cabbage, a fly, a fish, a lizard, a guinea pig, a cat, a dog, a monkey and a baby chimpanzee. In the unlikely case that you should experience no greater inhibitions in killing the chimpanzee than in destroying the cabbage or the fly, my advice to you is to commit suicide at your earliest possible convenience, because you are a weird monstrosity and a public danger.

The scientist knows very well that he is approaching ultimate truth only in an asymptotic curve and is barred from ever reaching it; but at the same time he is proudly aware of being indeed able to determine whether a statement is a nearer or a less near approach to the truth.

One of the most dangerously vicious circles menacing the continued existence of all mankind arises through that grim striving for the highest possible position within the ranked order, in other words, the reckless pursuit of power which combines with an insatiable greed of neurotic proportions that the results of acquired power confer.

I believe that present day civilized man suffers from insufficient discharge of his aggressive drive

It ought to be realized by all dog owners that obesity shortens a dog's life quite considerably, a life which is much too short anyhow.

Man has been driven out of the paradise in which he could trust his instincts.

Every man gets a narrower and narrower field of knowledge in which he must be an expert in order to compete with other people. The specialist knows more and more about less and less and finally knows everything about nothing.