So far I have been speaking of theoretical science, which is an attempt to understand the world. Practical science, which is an attempt to change the world, has been important from the first, and has continually increased in importance, until it has almost ousted theoretical science from men's thoughts.

A happy life must be to a great extent a quiet life, for it is only in an atmosphere of quiet that true joy dare live.

Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical.

Through the greatness of the universe, which philosophy contemplates, the mind also is rendered great, and becomes capable of that union with the universe which constitutes its highest good.

As soon as we abandon our own reason, and are content to rely upon authority, there is no end to our trouble. . . . No Catholic, for instance, takes seriously the text which says that a Bishop should be the husband of one wife.

Envy, in fact, is one form of a vice, partly moral, partly intellectual, which consists in seeing things never in themselves, but only in their relations.

A man who has once perceived, however temporarily and however briefly, what makes greatness of soul, can no longer be happy if he allows himself to be petty, self-seeking, troubled by trivial misfortunes, dreading what fate may have in store for him. The man capable of greatness of soul will open wide the windows of his mind, letting the winds blow freely upon it from every portion of the universe.