Full Idea
If a man eighty thousand years old were conceivable, his character would in fact be absolutely variable. …The brevity of human life misleads us…
Gist of Idea
Over huge periods of time human character would change endlessly
Source
Friedrich Nietzsche (Human, All Too Human [1878], 041)
Book Reference
Nietzsche,Friedrich: 'Human, All Too Human', ed/tr. Faber,Marion [Penguin 1994], p.45
A Reaction
This would be one of my many exhibits for claiming Nietzsche as an existentialist. I think he is largely right, and we do detect slow shifts in our characters over long periods of time. They may be as much a response to culture as a personal matter.