The man who makes everything that leads to happiness depends upon himself, and not upon other men, has adopted... — Plato
The man who makes everything that leads to happiness depends upon himself, and not upon other men, has adopted the very best plan for living happily. This is the man of moderation, the man of manly character and of wisdom.
Author: Plato
Insight: Most people chase happiness by collecting the right friends, job, or life circumstances—but that's actually a recipe for disappointment. Real stability comes from building things internally that can't be taken away: your reactions, your standards, your peace of mind. It's not selfish isolation; it's refusing to hand over your happiness to a world you can't control.
Source: Republic, Book VIII