Happiness belongs to those who are sufficient unto themselves. For all external sources of happiness and pleasure are, by their very nature, highly uncertain, precarious, ephemeral and subject to chance.

Whether we are in a pleasant or a painful state depends, finally, upon the kind of matter that pervades and engrosses our consciousness and what we compare it to - better and we envious and sad, worse and we feel grateful and happy.

He who does not enjoy solitude will not love freedom.

Sexual passion is the cause of war and the end of peace, the basis of what is serious... and consequently the concentration of all desire

That which knows all things and is known by none is the subject.

We should comfort ourselves with the masterpieces of art as with exalted personages-stand quietly before them and wait till they speak to us.

When a new truth enters the world, the first stage of reaction to it is ridicule, the second stage is violent opposition, and in the third stage, that truth comes to be regarded as self-evident.