He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has.

On the walls of the cave, only the shadows are the truth.

To the timid and hesitating everything is impossible because it seems so.

Only a life lived for others is a life worthwhile.

Nothing is so strong as gentleness. Nothing is so gentle as real strength.

Learn everything that is good from others, but bring it in, and in your own way absorb it; do not become others.

Science is a wonderful thing if one does not have to earn one's living at it.