Scientific truth is universal, because it is only discovered by the human brain and not made by it, as art is.

The truth about an animal is far more exciting and altogether more beautiful than all the myths woven about it.

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.

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.

All the advantages that man has gained from his ever-deepening understanding of the natural world that surrounds him, his technological, chemical and medical progress, all of which should seem to alleviate human suffering... tends instead to favor humanity's destruction.

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

The appeal of the cat lies in the very fact that she has formed no close bond with [man], that she has the uncompromising independence of a tiger or a leopard while she is hunting in his stables and barns: that she still remains mysterious and remote when she is rubbing herself gently against the legs of her mistress or purring contentedly in front of the fire.