Power Over Mind

Marcus Aurelius — Meditations

You have power over your mind—not outside events. Realize this, and you will find strength in the understanding that external circumstances cannot disturb your inner peace.

Written around 170-180 AD as private notes to himself, Marcus Aurelius' Meditations is one of the most enduring works of Stoic philosophy. This passage distills the core Stoic claim: we cannot control external events, only our judgments about them. As Roman emperor, Aurelius returned to this idea constantly as a discipline for governing under pressure.