Old age (n.) is the ripest time for poetry, not youth: life's interests are still there, but as shadows, not passions.
Old age (n.) is dwelling more and more within oneself and one's general ideas, until interest — inter-esse — falls away into contented, processless habit.
Old age (n.) comes when life's diversity sinks into habit and regularity, ending the tension that sustains life; death is just such a hardening against that tension.
Old age (n.) is the animal's self-inflicted death: reaching only an abstract universality, it blunts its activity, grows ossified, and kills itself by itself.
Old age (n.) completes our unity with the world — on one side sinking into the inertia of deadening habit, on the other freed from the petty entanglements of the present.