It is by acts and not by ideas that people live.

We find it hard to picture to ourselves the state of mind of a man of older days who firmly believed that the Earth was the centre of the Universe, and that all the heavenly bodies revolved around it. He could feel beneath his feet the writhings of the damned amid the flames; very likely he had seen with his own eyes and smelt with his own nostrils the sulphurous fumes of Hell escaping from some fissure in the rocks. Looking upwards, he beheld ... the incorruptible firmament, wherein the stars hung like so many lamps.

Truth possesses within herself a penetrating force, unknown alike to error and falsehood. I say 'truth' and you understand my meaning. For the beautiful words truth and justice need not to be defined in order to be understood in their true sense.

In order that knowledge be properly digested it must have been swallowed with a good appetite.

Dog! When we first met on the highway of life, we came from the two poles of creation.... What can be the meaning of the obscure love for me that has sprung up in your heart?

Universal peace will be realized, not because man will become better, but because a new order of things, a new science, new economic necessities, will impose peace.

If fifty million people say a foolish thing, it is still a foolish thing.