Stoicism: Living According to Nature

The foundational insight of Stoicism is the distinction between what is "up to us" (eph' hêmin) and what is "not up to us." According to Epictetus — a former slave who had experienced the most extreme version of what it means to have things outside your control — the only things truly up to us are our judgments, desires, intentions, and responses. Everything external — our bodies, reputation, wealth, the actions of others — is not up to us.

This might sound like a counsel of resignation. It is not. The Stoic claim is not that external things don't matter, but that our distress about external things comes from how we think about them, not from the things themselves. "It is not things that upset us," Epictetus wrote, "but our judgments about things." The person who is devastated by losing her job suffers not from the job loss itself — which is a brute fact — but from her judgment that the job was necessary for her happiness. Change the judgment, and the suffering changes.

The dichotomy of control is a demanding practice, not just an intellectual position. The Stoics recommended daily exercises: imagining the worst-case scenario (premeditatio malorum) so that it loses its power to shock; practicing voluntary discomfort (sleeping on the floor, skipping meals) to build tolerance for adversity; evening reviews of how well you maintained equanimity during the day. It is a philosophy designed for the long haul of a human life, not for moments of inspiration.

The Stoics believed the universe was governed by a rational principle — the logos — that structured all of reality. This logos was both the ordering intelligence of the cosmos and the rational faculty in each human being. To live according to nature was to align your rational faculty with the cosmic logos — to live in accordance with reason.

This gave Stoicism its distinctive ethical character. If reason is the divine element in humans, then anything that harms our rational faculty — excessive passion, irrational desire, fear of the inevitable — is vice. Anything that exercises and expresses reason well is virtue. And virtue alone is sufficient for eudaimonia. External goods — health, wealth, reputation — are "preferred indifferents": we can reasonably prefer them and pursue them, but we should not mistake them for the good itself.

The Stoic sage — the ideal type fully aligned with logos — was a theoretical ideal rather than a description of any actual person. But the Stoics were clear that approximating the sage was the project of a lifetime, achievable through sustained practice. Marcus Aurelius' Meditations, written as private notes to himself, are the record of a Roman emperor trying — imperfectly, daily — to live up to this ideal.

Marcus Aurelius reigned as Emperor of Rome from 161 to 180 CE — one of the most powerful human beings who has ever lived. He spent much of his reign on military campaigns in the cold and rain of the Germanic frontier, far from Rome, dealing with plagues, rebellions, and the constant pressure of command. His Meditations — never intended for publication — are his private philosophical diary, written in Greek, recording his attempts to apply Stoic principles to the actual conditions of his life.

What makes the Meditations extraordinary is their honesty. Marcus does not present himself as a sage. He writes to himself in the second person — "You are angry again. You are letting vanity get the better of you" — as if holding himself to account before an audience of one. He reminds himself, repeatedly, of the same lessons: that death is nothing to fear; that fame is fleeting; that the opinions of others should not disturb him; that the only thing worth caring about is acting virtuously, now, in this moment.

The Meditations have never gone out of print. Generals, CEOs, athletes, and prisoners have found in them a practical guide that addresses the situation of human beings — powerful or powerless — with remarkable honesty. Stoicism's modern revival owes much to Marcus and to the recognition that a philosophy developed in a painted porch in Athens may be as useful in the 21st century as it was in the 1st.