What are the four Stoic virtues?

Marcus Aurelius names the four together in his private notebook: "justice, truth, temperance, fortitude" (Meditations 3.6). This is the classical Stoic list, usually translated as wisdom, justice, courage, and moderation or self-discipline. Wisdom is the knowledge of what is good, bad, and neither. Justice is giving each person and thing its due, and in the Stoic view, treating other rational beings as made for cooperation rather than use. Courage, sometimes called fortitude, is steadiness in the face of pain, danger, or loss. Moderation, or temperance, is right measure in the face of pleasure and desire.

The common misreading is to hear these as four separate skills you might rank or trade off, the way you might be strong but not disciplined, or brave but not wise. The Stoics denied this. Virtue is a single, unified knowledge of how to live, and the four names pick out that same knowledge as it shows up in different situations. A person acting with genuine courage cannot be acting foolishly or unjustly at the same moment, because courage that ignores justice is not courage at all, it is recklessness. This is why Marcus can list them almost interchangeably with "your own mind's self-satisfaction in the things which it enables you to do according to right reason" (Meditations 3.6). The four virtues are one thing, reason operating well, seen from four angles.

A second misreading treats the virtues as one good thing among others, alongside health, wealth, or reputation, each contributing its share to a happy life. Marcus rules this out directly. He distinguishes people who have genuinely conceived prudence, temperance, justice, and fortitude as good from people who only apply that word to wealth or the comforts that come with it, and he says even ordinary people can feel the difference when a joke about wealth's absurdity lands, but would never accept the same joke about justice (Meditations 5.12). The test he proposes is simple: would you take the joke if it were made about virtue itself. If not, you already sense that virtue is not on the same scale as money or comfort. It is not a large good among small goods. It is the only good.

This is the stronger and more demanding claim. The Stoics did not say virtue matters most among several important things. They said virtue is what makes a life good or bad, full stop, and everything else, health, reputation, pleasure, pain, is indifferent to that question, useful or not as raw material but never itself the measure. That is a hard teaching to sit with, because it means a person who has lost everything except their judgment and their choices has lost nothing that actually mattered, and a person who has every comfort but acts unjustly has nothing of value at all.

What follows from this for justice specifically deserves its own note, because Marcus treats it as the load-bearing virtue among the four. He argues that acting unjustly, and even lying, is a kind of impiety against the rational nature that made human beings for one another, not to injure one another (Meditations 9.1). Elsewhere he traces all the virtues back to it: universal nature does the lesser things for the sake of the greater, and this is why justice comes first, since "in justice the other virtues have their foundation" (Meditations 11.10). Wisdom without justice curdles into cleverness. Courage without justice becomes cruelty. Moderation without justice is just private tidiness.

The practical upshot is a daily test, not a slogan. Before you call something good, ask which of the four virtues it actually serves, and whether you would still call it good if it cost you comfort, money, or reputation instead of granting them. If the honest answer is that you value it only because it pays out in externals, you have found a preferred indifferent, not a good.