With ordinary men the moments which are united in a close continuity out of the original discrete multiplicity are very few, and the course of their … - Otto Weininger

As the mental endowment of a man varies with the organisation of his accumulated experiences, the better endowed he is, the more readily will he be able to remember his whole past, everything that he has ever thought or heard, seen or done, perceived or felt, the more completely in fact will he be able to reproduce his whole life. Universal remembrance of all its experiences, therefore, is the surest, most general, and most easily proved mark of a genius.

In men of genius, sterile years precede productive years, these again to be followed by sterility, the barren periods being marked by psychological self-depreciation, by the feeling that they are less than other men; times in which the remembrance of the creative periods is a torment, and when they envy those who go about undisturbed by such penalties. Just as his moments of ecstasy are more poignant, so are the periods of depression of a man of genius more intense than those of other men [Wie seine Ekstasen gewaltiger sind als die der anderen, so sind auch seine Depressionen fürchterlicher]. Every great man has such periods, of longer or shorter duration, times in which he loses self-confidence, … times in which, indeed, he may be sowing the seeds of a future harvest, but which are devoid of the stimulus to production.

The psychical condition of men’s minds may be compared with a set of bells close together, and so arranged that in the ordinary man a bell rings only when one beside it sounds, and the vibration lasts only a moment. In the genius, when a bell sounds it vibrates so strongly that it sets in action the whole series, and remains in action throughout life. The latter kind of movement often gives rise to extraordinary conditions and absurd impulses, that may last for weeks together and that form the basis of the supposed kinship of genius with insanity.