So Nietzsche argues, but more often, for he returns on various occasions to this idea, led thereto by his customary aristocratic leanings, he speaks of democracy as of a form of decadence, as a necessary prelude to an aristocracy of the future. "A high civilisation can only be built upon a wide expanse of territory, upon a healthy and firmly consolidated mediocrity." [So he wrote in 1887. Ten years earlier he held that slavery had been the necessary condition of the high civilisation of Greece and Rome.] The only end, therefore, which at present, provisionally of course but still for a long time to come, we have to expect, must be the decadence of mankind--general decadence to a level mediocrity, for it is necessary to have a wide foundation on which a race of strong men can be reared. "The decadence of the European is the great process which we cannot hinder, which we ought rather to accelerate. It is the active cause at work which gives us hope of seeing the rise of a stronger race, a race which will possess in abundance those same qualities which are lacking to the degenerate vanishing species, strength of will, responsibility, self-reliance, the power of concentration...." But how, out of this mediocrity of the crowd, a mediocrity which, as Nietzsche says, is always increasing, by what process natural or artificial can a new and superior race be created? Nietzsche seems to be recalling the theory, very disrespectful and very devoid of filial piety, by which Renan sought to explain his own genius. "A long line of obscure ancestors," he says, "has economised for me a store of intellectual energy," and he jots down in his note book certain suggestions, a little immature but still emitting a ray of light. "It is absurd," he says, "to imagine that this victory or survival of values (that is low values, values, that is, that seem to be mediocrity) can be antibiological: we must look for an explanation in the fact that they are probably of some vital importance to the maintenance of the type 'man' in the event of its being threatened by a preponderance of the feeble-minded and degenerate. Perhaps if things went otherwise, man would now be an extinct animal. The elevation of type is dangerous for the preservation of the species. Why? _Strong races are wasteful, we find ourselves here confronted with a problem of economy._"