From Mencken’s The Philosophy of Friedrich Nietzsche–
Acutely aware of his own superiority, he showed no patience with the unctuous complacency of dons and dignitaries, and so he became embroiled in various conflicts, and even his admirers among his colleagues seldom ventured upon friendly advances.
There are critics who see in all this proof that Nietzsche showed signs of insanity from early manhood, but as a matter of fact it was his abnormally accurate vision and not a vision gone awry, that made him stand so aloof from his fellows. In the vast majority of those about him he saw the coarse metal of sham and pretense beneath the showy gilding of learning. He had before him, at close range, a good many of the great men of his time—the intellectuals whose word was law in the schools. He saw them on parade and he saw them in their shirt sleeves. What wonder that he lost all false reverence for them and began to estimate them in terms, not of their dignity and reputation, but of their actual credibility and worth? It was inevitable that he should compare his own ideas to theirs, and it was inevitable that he should perceive the difference between his own fanatical striving for the truth and the easy dependence upon precedent and formula which lay beneath their booming bombast. Thus there arose in him a fiery loathing for all authority, and a firm belief that his own opinion regarding any matter to which he had given thought was as sound, at the least, as any other man’s. Thenceforth the assertive “ich” began to besprinkle his discourse and his pages. “I condemn Christianity. I have given to mankind…. I was never yet modest…. I think…. I say…. I do….” Thus he hurled his javelin at authority until the end.