So far there has been no philosopher in whose hands philosophy has not grown into an apology for knowledge; on this point, at least, every one is an optimist, that the greatest usefulness must be ascribed to knowledge. They are all tyrannized over by logic, and this is optimism in its essence.

Only with the ultimate knowledge of all things will man have come to know himself. For things are but the boundaries of man.

Invisible threads are the strongest ties.

What is bad? -Everything that arises from weakness.

I have learned to walk: ever since, I let myself run. I have learned to fly: ever since, I do not want to be pushed before moving along.

As soon as a religion comes to dominate it has as its opponents all those who would have been its first disciples.

There is one thing one has to have either a soul that is cheerful by nature, or a soul made cheerful by work, love, art, and knowledge.