Marcel Proust quote from restisnoise.com

Because [Mme de Cambremer] considered herself "advanced," because (in matters of art only) "one could never be far enough to the Left," she maintained not merely that music progressed, but that it progressed along a single straight line, and that Debussy was in a sense a super-Wagner, slightly more advanced again than Wagner. She did not realize that if Debussy was not as independent of Wagner as she herself was to suppose in a few years' time, because an artist will after all make use of the weapons he has captured to free himself finally from one whom he has momentarily defeated, he nevertheless sought, when people were beginning to feel surfeited with works that were too complete, in which everything was expressed, to satisfy an opposite need. There were theories, of course, to bolster this reaction temporarily, like those theories which, in politics, come to the support of the laws against the religious orders, or of wars in the East (unnatural teaching, the Yellow Peril, etc., etc.). People said that an age of speed required rapidity in art, precisely as they might have said that the next war could not last longer than a fortnight, or that the coming of railways would kill the little places beloved of the coaches, which the motor-car was none the less to restore to favor. Composers were warned not to strain the attention of their audience, as though we had not at our disposal different degrees of attention, among which it rests precisely with the artist himself to arouse the highest. For those who yawn with boredom after ten lines of a mediocre article have journeyed year after year to Bayreuth to listen to the Ring. In any case, the day was to come when, for a time, Debussy would be pronounced as flimsy as Massenet, and the agitations of Mélisande degraded to the level of Manon's. For theories and schools, like microbes and corpuscles, devour one another and by their strife ensure the continuity of life. But that time was still to come.