Mannerism is always longing to have done, and has no true enjoyment in work. A genuine, really great talent, on the other hand, has its greatest happiness in execution.

Excellence is rarely found, more rarely valued.

Let everyone sweep in front of his own door, and the whole world will be clean.

It seems to me that every phenomenon, every fact, itself is the really interesting object. Whoever explains it, or connects it with other events, usually only amuses himself or makes sport of us, as, for instance, the naturalist or historian. But a single action or event is interesting, not because it is explainable, but because it is true.

To become aware in time when young of the advantages of age; to maintain the advantages of youth in old age: both are pure fortune.

Great passions are incurable diseases.

The use of a thing is only a part of its significance. To know anything thoroughly, to have the full command of it in all its appliances, we must study it on its own account, independently of any special application.