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.

The fidelity of a dog is a precious gift demanding no less binding moral responsibilities than the friendship of a human being.

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.

Evil, by definition, is that which endangers the good, and the good is that which we perceive as a value.

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.

The human soul is very much older than the human mind.

Few animals display their mood via facial expressions as distinctly as cats.