Search men’s governing principles, and consider the wise, what they shun and what they cleave to.

This line is typically attributed to Marcus Aurelius’ private Stoic notebook, later known as the Meditations, written in Greek during his reign as Roman emperor (161–180 CE), much of it composed while on military campaigns along the Danube frontier. In these notes Marcus repeatedly trains himself to look past reputation, rhetoric, and social display to the “ruling principle” (hegemonikon)—the inner faculty of judgment and choice that Stoics regarded as the core of moral character. The remark fits his recurring practice of evaluating people (and himself) by their governing aims and aversions rather than by status or outward success.

Marcus urges a diagnostic way of reading character: to understand someone, examine what ultimately directs their choices—their governing principles—and observe what the genuinely wise avoid and pursue. In Stoic terms, wisdom is revealed less by what one says than by one’s patterns of assent, desire, and avoidance: the wise “shun” moral error (false judgments, uncontrolled passions, injustice) and “cleave to” what is up to them—virtue, rational action, and integrity. The quote also functions as self-advice: by scrutinizing one’s own guiding commitments, one can correct misdirected desires and align life with reason and the common good.