There is not really any courage at all in attacking hoary or antiquated things, any more than in offering to fight one's grandmother. The really courageous man is he who defies tyrannies young as the morning and superstitions fresh as the first flowers. The only true free-thinker is he whose intellect is as much free from the future as from the past.
Something might be true while being harmful and dangerous in the highest degree. Indeed, it might be a basic characteristic of existence that those who know it completely would perish, in which case the strength of a spirit should be measured according to how much of the 'truth' one could still barely endure- or to put it more clearly, to what degree one would require it to be thinned down, shrouded, sweetened, blunted, falsified.
The new school of art and thought does indeed wear an air of audacity, and breaks out everywhere into blasphemies, as if it required any courage to say a blasphemy. There is only one thing that it requires real courage to say, and that is a truism.