Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.

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.

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

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.

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

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

The fidelity of a dog is a precious gift.