Serenity of spirit and turbulence of action should make up the sum of a man's life.

The aphorism proposes an ideal balance: an inward steadiness paired with outward energy. “Serenity of spirit” suggests emotional self-command, perspective, and an inner life not easily shaken by circumstance. “Turbulence of action” points to a life of vigorous engagement—risk, effort, and decisive movement in the world. Put together, the line argues that a full life is not quietism; it is active and even stormy in deeds, but governed by a calm center. The gendered “man” reads as a conventional universal of its period rather than a strict limitation, framing a general ethic of composed intensity.