What is uttered from the heart alone, Will win the hearts of others to your own.

Doubt can only be removed by action.

The theater has often been at variance with the pulpit; they ought not to quarrel. How much is it to be wished that in both the celebration of nature and of God were intrusted to none but men of noble minds.

There is nothing outside of us that is not at the same time in us, and as the external world has its colors the eye, too, has colors.

What must the English and French think of the language of our philosophers when we Germans do not understand it ourselves?

All theory, dear friend, is gray, but the golden tree of life springs ever green.

Thinking is easy, acting is difficult, and to put one's thoughts into action is the most difficult thing in the world.