It is only when a man is alone that he is really free.

The intellectual attainments of a man who thinks for himself resemble a fine painting, where the light and shade are correct, the tone sustained, the colour perfectly harmonised; it is true to life. On the other hand, the intellectual attainments of the mere man of learning are like a large palette, full of all sorts of colours, which at most are systematically arranged, but devoid of harmony, connection and meaning.

To be alone is the fate of all great minds—a fate deplored at times, but still always chosen as the less grievous of two evils.

Empirical sciences prosecuted purely for their own sake, and without philosophic tendency are like a face without eyes.

A pessimist is an optimist in full possession of the facts.

The ultimate foundation of honor is the conviction that moral character is unalterable: a single bad action implies that future actions of the same kind will, under similar circumstances, also be bad.

The difficulty is to try and teach the multitude that something can be true and untrue at the same time.