and true progress. Last comes a stage when retentiveness is exhausted and all that happens is at once forgotten; a vain, because unpractical, repetition of the past takes the place of plasticity and fertile readaptation. In a moving world readaptation is the price of longevity. The hard shell, far from protecting the vital principle, condemns it to die down slowly and be gradually chilled; immortality in such a case must have been secured earlier, by giving birth to a generation plastic to the contemporary world and able to retain its lessons. Thus old age is as forgetful as youth, and more incorrigible; it displays the same inattentiveness to conditions; its memory becomes self-repeating and degenerates into an instinctive reaction, like a bird’s chirp.
Not all readaptation, however, is progress, for ideal identity must not be lost. The Latin language did not progress when it passed into Italian. It died. Its amiable heirs may console us for its departure, but do not remove the fact that their parent is extinct. So every individual, nation, and religion has its limit of adaptation; so long as the increment it receives is digestible, so long as the organisation already attained is extended and elaborated without being surrendered, growth goes on; but when the foundation itself shifts, when what is gained at the periphery is lost at the centre, the flux appears again and progress is not real. Thus a succession of generations or languages or relig-
