The great man of science, unless he is also a philosopher, … deserves the title of genius as little as the man of action. - Otto Weininger

That which enables man to have a real relation to truth and which removes his temptation to lie, must be something independent of all time, something absolutely unchangeable, which as faithfully reproduces the old as if it were new, because it is permanent itself; it can only be that source in which all discrete experiences unite and which creates from the first a continuous existence. It is what produces the feeling of responsibility which oppresses all men, young and old, as to their actions, which makes them know that they are responsible, which leads to the phenomena of repentance and consciousness of sin, which calls to account before an eternal and ever present self things that are long past, its judgment being subtler and more comprehensive than that of any court of law or of the laws of society, and which is exerted by the individual himself quite independently of all social codes (so condemning the moral psychology which would derive morality from the social life of man).

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.

Colour-blindness always extends to the complementary colours. Those who are red blind are also green blind; those who are blind to blue have no consciousness of yellow. This law holds good for all mental phenomena; it is a fundamental condition of consciousness.