One must need to be strong, otherwise one will never become strong.

On the mountains of truth you can never climb in vain: either you will reach a point higher up today, or you will be training your powers so that you will be able to climb higher tomorrow.

Every achievement, every step forward in knowledge, is the consequence of courage, of toughness towards oneself, of sincerity to oneself

That the world is not the embodiment of an eternal rationality can be conclusively proved by the fact that the piece of the worldthat we know--I mean our human reason--is not so very rational. And if it is not eternally and completely wise and rational, then the rest of the world will not be either; here the conclusion a minori ad majus, a parte ad totum applies, and does so with decisive force.

What doesn't kill you make you stronger.

Men are cowards when it comes to the "eternally feminine": and the little women know it.

When on a Sunday morning we hear the old bells ring out, we ask ourselves, "Is it possible! This is done on account of a Jew crucified two thousand years ago who said he was the Son of God. The proof of such an assertion is wanting".