virtue” sounds a bit pompous, the Greek word for it, arete, is arguably better translated as “excellence of character.” Something excels, in this sense, if it performs its function well. Humans excel when they think clearly and reason well about their lives, which amounts to living wisely. The Stoics adopted the Socratic division of cardinal

In other words, the wise man extends moral consideration to all rational creatures and views them, in a sense, as his brothers and sisters. That’s why the Stoics described their ideal as cosmopolitanism, or being “citizens of the universe”—a phrase attributed both to Socrates and Diogenes the Cynic.

How therefore does it profit a man, the Stoics might say, if he gains the whole world but loses his wisdom and virtue?

The true goal of life for Stoics isn’t to acquire as many external advantages as possible but to use whatever befalls us wisely, whether it be sickness or health, wealth or poverty, friends or enemies. The Stoic Sage, or wise man, needs nothing but uses everything well; the fool believes himself to “need” countless things, but he uses them all

For instance, wisdom may tell us that wealth is generally preferable to debt, but valuing money more highly than justice is a vice. In

Today many students of Stoicism adopt a similar attitude: they’re attracted to the Stoic worldview but prefer to “update” it by drawing upon a wider range of arguments from modern science and philosophy.

Zeno’s attitude to his students perhaps resembled the one later described by Seneca, who did not claim to be an expert like a physician but saw his role more like that of a patient describing the progress of his treatment to fellow patients in the hospital beds beside him.

Stoicism therefore evolved out of Cynicism, and the two traditions remained very closely associated right down to the time of Marcus Aurelius.

Nevertheless, the Stoics taught that the wise man is naturally inclined to write books that help other people.