Be scrupulously truthful, even if the truth is inconvenient, for it is more inconvenient when you try to conceal it.

Understanding human nature must be the basis of any real improvement in human life. Science has done wonders in mastering the laws of the physical world, but our own nature is much less understood, as yet, than the nature of stars and electrons. When science learns to understand human nature, it will be able to bring a happiness into our lives which machines and the physical sciences have failed to create.

Religion and Science are two aspects of social life, of which the former has been important as far back as we know anything of man

Fervent religious believers sacrifice pleasures of the body, but instead enjoy pleasures of the mind, including the joy of knowing that those men who didn't follow their religion would be tortured for eternity.

The man who has fed the chicken every day throughout its life at last wrings its neck instead, showing that more refined views as to the uniformity of nature would have been useful to the chicken.

The human animal, like others, is adapted to a certain amount of struggle for life [and] the mere absence of effort from his life removes an essential ingredient of happiness. [. . .] He forgets that to be without some of the things you want is an indispensable part of happiness.

When the state intervenes to insure the indoctrination of some doctrine, it does so because there is no conclusive evidence in favor of that doctrine.