Full Idea
What makes existence desirable is the consciousness of one's own goodness, and such consciousness is pleasant in itself.
Gist of Idea
Existence is desirable if one is conscious of one's own goodness
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1170b09)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.306
A Reaction
Nowadays we are much more conscious than Aristotle was of vanity as a vice, probably thanks to Christianity. The smugness of virtue signalling is especially annoying. But you see his point.