For more information on Stoicism see my latest book How to Think Like a Roman Emperor: The Stoic Philosophy of Marcus Aurelius.
The Stoics often refer to the four cardinal virtues of Greek philosophy: prudence, justice, fortitude, and temperance. (Or if you prefer: wisdom, morality, courage, and moderation.)
We don’t know where this classification originated. It appears to go back as far as Plato or Socrates, although probably even further. This was a very ancient, conventional schema for understanding virtue. The Stoics don’t appear to have assumed it was the only or the best way to conceptualize the virtues. They often prefer to think of virtue, from a slightly different perspective, as living in harmony with Nature at three different levels. In some ways these models overlap.
However, the cardinal virtues have remained popular as a way of interpreting ancient philosophical ethics throughout the ages. One of my hesitations about introducing newcomers to Stoicism through this model is that the Greek words are difficult to translate into modern English and the meanings were probably also somewhat stretched by the Stoics to fit their philosophy. It’s a slightly ill-fitting classification, although it’s simple and appealing, so we shouldn’t get to hung up on taking it literally, as if these words provide the only way to describe virtue.
People often wrangle over the definitions of Greek philosophical terms, which can lead to some rather speculative translations. Believe it or not, though, we actually have a Greek philosophical dictionary that survives from the time of Plato. It’s called Definitions, and is believed to have probably been written by one of Plato’s followers at the Academy. So these are not Stoic definitions of the virtues but knowing how Platonists defined them certainly helps us a lot. For instance, this is how the Academy defined the word “virtue” itself:
aretê (virtue/excellence). The best disposition; the state of a mortal creature which is in itself praiseworthy; the state on account of which its possessor is said to be good; the just observance of the laws; the disposition on account of which he who is so disposed is said to be perfectly excellent; the state which produces faithfulness to law.
It’s also worth mentioning the notoriously tricky eudaimonia, which is conventionally rendered as “happiness”, although most scholars agree that’s a misleading translation. Its meaning is closer to the archaic sense of the word “happiness”, which was the opposite of hapless, wretched or unfortunate. A better translation would be “fulfillment” or “flourishing”, as you can see from the Academic definition.
eudaimonia (happiness/fulfilment). The good composed of all goods; an ability which suffices for living well; perfection in respect of virtue; resources sufficient for a living creature.
This will be a slightly more scholarly blog post than some. I’ve listed the four cardinal virtues below with the definitions from the Academy and also some notes on what the early Stoic fragments say in Diogenes Laertius, Stobaeus, etc. I’ve not referenced everything extensively here, though, for the sake of brevity. (It’s just a quick blog post.) You’ll find most of this information in the Stoic fragments from Diogenes Laertius and Stobaeus, though, and in Pierre Hadot’s Inner Citadel and A.A. Long’s Epictetus.
The Cardinal Virtues
phronêsis (prudence/practical wisdom)
The ability which by itself is productive of human happiness; the knowledge of what is good and bad; the knowledge that produces happiness; the disposition by which we judge what is to be done and what is not to be done.
In a sense, all of the virtues can be understood as wisdom applied to our actions, or moral wisdom. Prudence is the most important and most general of the Stoic virtues because it refers, as here, to the firmly-grasped knowledge of what is good, bad, and indifferent in life. In other words, understanding the most important things in life or grasping the value of things rationally. It’s opposite is the vice of ignorance. Most crucially for Stoics it means firmly grasping the nature of the good: understanding that virtue or wisdom itself is the only true good, and living accordingly. Prudence is therefore closely related to the very meaning of the word “philosophy”: love of wisdom.
However, it can also refer to our ability to discern the value (axia) of different external things rationally, i.e., distinguishing wisely between different “preferred indifferents”. (A point discussed in detail by the Stoic Cato of Utica in Cicero’s De Finibus.) Marcus refers to this as acting and responding to things “in accord with value”. Stobaeus likewise says the early Stoics defined it as knowing the nature of the good and bad, understanding indifferent things, and knowing what would be “appropriate action” under different circumstances. Diogenes Laertius says that Chrysippus and others sub-divided prudence into good counsel (euboulia) and understanding (sunesis). That’s intriguing because it links prudence to Stoic Rhetoric, and the ability to communicate the truth appropriately to other people, honestly but tactfully, such as the way Marcus described his wise Stoic teachers expressing their doctrines. It’s also clear that the Stoics believed the wise man is able to offer himself good counsel.
The Stoics divided their curriculum into three: Logic, Ethics, and Physics. They may have linked Prudence with the topic of Stoic Logic, which encompassed epistemology and psychology, and appears related to the practices that Epictetus called the Discipline of Assent.
The unanimity of the soul with itself, and the good discipline of the parts of the soul with respect to each other and concerning each other; the state that distributes to each person according to what is deserved; the state on account of which its possessor chooses what appears to him to be just; the state underlying a law-abiding way of life; social equality; the state of obedience to the laws.
This is perhaps the most problematic translation. Our modern word “justice” seems too formal or narrow for what the Stoics meant. The Stoics don’t just mean what’s just in the legal sense but what would be moral in our dealings with others more generally. For instance, they take it to encompass a mother’s attitude toward her children or our sense of piety toward the gods. In the past it was therefore often translated more broadly as “righteousness”, or some modern authors simply refer to it as social virtue or morality. Its opposing vice occurs when we are unjust or do wrong by another person morally.
We’re told that it was composed mainly of the subordinate virtues of kindness and fairness. So although it may not be apparent from the word “justice” this is a much broader concept of social virtue, which encompasses the numerous references to kindness, benevolence, or goodwill toward others found in Stoic writings, particularly throughout The Meditations of Marcus Aurelius. Indeed, Marcus actually says that justice is the most important of the virtues.
You can view justice largely as moral wisdom applied to our actions, particularly in relation to other people individually or society as a whole. Stobaeus says that it is the knowledge of the distribution of proper value to each person or fair “distributions”, i.e., in relation to preferred indifferents (external things). Diogenes Laertius says the Stoics divided justice mainly into impartiality (isotês) and kindness/courtesy (eugnômosunê). It may have correlated with the Stoic topic of Ethics, including politics, and what Epictetus calls the applied Discipline of Action (or Impulse to Act, referring to our voluntary intentions).
Moderation of the soul concerning the desires and pleasures that normally occur in it; harmony and good discipline in the soul in respect of normal pleasures and pains; concord of the soul in respect of ruling and being ruled; normal personal independence; good discipline in the soul; rational agreement within the soul about what is admirable and contemptible; the state by which its possessor chooses and is cautious about what he should.
This is also a slightly difficult term in some ways. It refers to moderation or self-discipline/self-control but also to self-awareness or being self-possessed. We could even view it as closely related to what many people today mean by “mindfulness”. It’s the opposite of the vice called “wantonness” or “licentiousness”. The many references to appropriate feelings of “shame” in Epictetus are related to this virtue and we could view it as (very) loosely related to the Christian idea of moral conscience. Stobaeus says that it entails knowledge of “what is to be chosen, avoided, and neither” in the domain of “impulses”, i.e., it guides our intentions to act on certain desires. Diogenes Laertius says the Stoics defined moderation mainly as good self-discipline (eutaxia) and propriety/decorum (kosmistês).
Surprisingly, some academics, most notably Pierre Hadot, view this and fortitude as being the virtues corresponding with the topic of Stoic Physics and Epictetus’ applied Discipline of Fear and Desire, which we could also call the Stoic Therapy of the Passions. That’s easier to understand when we observe many of the Stoic exercises related to Physics and cosmology. By viewing events in a detached manner, like a natural philosopher or a physician, the Stoics aimed to achieve an “Objective Representation” of them, suspending any judgements of good or bad, and therefore eliminating fear and desire. Think of the modern notion of scientific detachment and objectivity. Likewise, Hadot refers to the Stoic practice of imagining the whole of space and time as the View from Above or cosmic perspective. This is obviously related to cosmology and Physics but the Stoics employed it to rise above their fears and desires and achieve apatheia or freedom from unhealthy passions and attachment to external things.
The state of the soul which is unmoved by fear; military confidence; knowledge of the facts of warfare; self-restraint in the soul about what is fearful and terrible; boldness in obedience to wisdom; being intrepid in the face of death; the state which stands on guard over correct thinking in dangerous situations; force which counterbalances danger; force of fortitude in respect of virtue; calm in the soul about what correct thinking takes to be frightening or encouraging things; the preservation of fearless beliefs about the terrors and experiences of warfare; the state which cleaves to the law.
This is one of the simpler virtues. It clearly means courage, although the Stoics also extend it to include endurance of pain and discomfort more generally. It’s the opposite of the vice of “cowardice”. It appears to form a pair with the virtue of moderation. Both refer to the master of passions: moderation to desires and courage to fears. Hence, they probably correlate also with Epictetus’ famous slogan: endure and renounce. The virtue of courage allows us to endure fear and the virtue of moderation to renounce unhealthy desires.
As Seneca observed, paradoxically, these virtues cannot exist without at least some trace of fear and desire for us to master, and the Stoics insist that even the perfect Sage requires moderation and courage because he is still subject to the first movements of passion or “proto-passions” (propatheiai). Seneca explains this in detail in On Anger and elsewhere but it’s also very vividly described by Epictetus, as recounted by Aulus Gellius’ story of the Stoic teacher caught in a storm at sea.
Stobaeus says the Stoics defined courage as knowledge of what is terrible, what is not terrible, and what is neither or “standing firm”, i.e., endurance guided by wisdom. Diogenes Laertius says they divided courage primarily into constancy/determination (aparallaxia) and tension/vigour (eutonia). This final virtue may correspond, alongside courage, with Stoic Physics, as described above, and also with Epictetus’ applied Discipline of Fear and Desire.