The fidelity of a dog is a precious gift.

Every mutation through a new combination of genetic factors that provides the organism with a new opportunity for coming to terms with the conditions of its environment signifies no more and no less than that new information about this environment has got into that organic system. Adaptation is essentially a cognitive process.

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

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

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.

...he who has seen the intimate beauty of nature cannot tear himself away from it again. He must become either a poet or a naturalist and, if his eyes are keen and his powers of observation sharp enough, he may well become both.