To understand a man is really to be that man. - Otto Weininger

In order to depict a man one must understand him, and to understand him one must be like him; in order to portray his psychological activities one must be able to reproduce them in oneself. To understand a man one must have his nature in oneself.

Universality is the distinguishing mark of genius. There is no such thing as a special genius, a genius for mathematics, or for music, or even for chess, but only a universal genius. … The theory of special genius, according to which for instance, it is supposed that a musical genius should be a fool at other subjects, confuses genius with talent. … There are many kinds of talent, but only one kind of genius, and that is able to choose any kind of talent and master it.

Great men take themselves and the world too seriously to become what is called merely intellectual. Men who are merely intellectual are insincere; they are people who have never really been deeply engrossed by things and who do not feel an overpowering desire for production. All that they care about is that their work should glitter and sparkle like a well-cut stone, not that it should illuminate anything. They are more occupied with what will be said of what they think than by the thoughts themselves.