“Old age is far more than white hair, wrinkles, the feeling that it is too late and the game finished, that the stage belongs to the rising generations. The true evil is not the weakening of the body, but the indifference of the soul. Upon crossing the shadow line, it is more the desire to act than the power to do so that is lost. Is it possible, after fifty years of experiences and disappointments, to retain the ardent curiosity of youth, the desire to know and understand, the power to love wholeheartedly, the certainty that beauty, intelligence, and kindness unite naturally, and to preserve faith in the efficacy of reason? Beyond the shadow line lies the realm of even, tempered light where the eyes, not being dazzled any more by the blinding sun of desire, can see things and people as they are. How is it possible to believe in the moral perfection of pretty women if you have loved one of them? How is it possible to believe in progress when you have discovered throughout a long and difficult life that no violent change can triumph over human nature and that it is only the most ancient customs and ceremonies that can provide people with the flimsy shelter of civilization? "What's the use?" says the old man to himself. This is perhaps the most dangerous phrase he can utter, for after having said: "What's the use of struggling?" he will say one day: "What's the use of going out?" then: "What's the use of leaving my room?" then: "What's the use of leaving my bed?" and at last comes "What's the use of living?"”

which opens the portals of death.
Un Art de Vivre (The Art of Living) (1939), The Art of Growing Old