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.

I believe-and human psychologists, particularly psychoanalysts should test this-that present-day civilized man suffers from insufficient discharge of his aggressive drive. It is more than probable that the evil effects of the human aggressive drives, explained by Sigmund Freud as the results of a special death wish, simply derive from the fact that in prehistoric times intra-specific selection bred into man a measure of aggression drive for which in the social order today he finds no adequate outlet.

The human mind, in taking us down the path of technocracy, has become the adversary of life itself and collaterally the adversary of the human soul.

Just thinking that my dog loves me more than I love him, I feel shame.

The instinctive need to be the member of a closely knit group fighting for common ideals may grow so strong that it becomes inessential what these ideals are.

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

All scientific knowledge to which man owes his role as master of the world arose from playful activities.