A man sufficiently gifted with humor is in small danger of succumbing to flattering delusions about himself, because he cannot help perceiving what a pompous ass he would become if he did.

Historians will have to face the fact that natural selection determined the evolution of cultures in the same manner as it did that of species.

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.

Man appears to be the missing link between anthropoid apes and human beings.

In nature we find not only that which is expedient, but also everything which is not so inexpedient as to endanger the existence of the species.

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.