In the superman Nietzsche gave the world a conceivable and possible goal for all human effort. But there still remained a problem and it was this: When the superman at last appears on earth, what then? Will there be another super-superman to follow and another super-super-superman after that? In the end, will man become the equal of the creator of the universe, whoever or whatever He may be? Or will a period of decline come after, with return down the long line, through the superman down to man again, and then on to the anthropoid ape, to the lower mammals, to the asexual cell, and, finally, to mere inert matter, gas, ether, and empty space?
H.L. Mencken, The Philosophy of Friedrich Nietzsche
evolution, superman