A glossary of Stoic terms and concepts

How to use this glossary

Even the name is a term. Zeno of Citium taught in Athens around 300 BCE at the Stoa Poikilē, the Painted Porch, and his followers were named after the building. The vocabulary stayed Greek; Roman Stoics such as Seneca, writing in Latin, either borrowed the Greek words or found Latin ones.

Each entry gives the term in a common transliteration, a plain meaning, and, where it helps, the English word George Long used for it. Long’s Meditations (1862) and his Epictetus (1877) are the main translations quoted on this site, alongside Aubrey Stewart’s Seneca, and some of Long’s words mislead a modern reader: his will is not willpower, and his appearance is not how something looks. There is more on how his English reads in the guide to Meditations translations.

The Stoics divided philosophy into logic, physics and ethics, and taught the three as one system (Stanford Encyclopedia of Philosophy (opens in a new tab)). The sections below follow that division, except that the terms for how the mind works get their own section, because that is where daily practice happens. Logic’s terms for arguments and propositions are left out. These ideas have longer pages of their own:

Ethics terms

Ethics was the part of philosophy that answered the practical question: what makes a human life go well?

Eudaimonia

The goal of life. It is usually translated happiness, but flourishing is closer: it describes how a whole life goes, not how a day feels. The major Greek schools agreed that eudaimonia was the goal and disagreed about what it consists of. The Stoic answer was virtue. The word literally means having a good daimōn, a good guiding spirit, and Marcus Aurelius plays on that literal sense in Meditations 7.17. See can Stoics be happy?

Telos and living according to nature

Telos is the end or aim, the thing everything else is done for. The Stoic statement of it comes in three versions. Zeno said the goal is living in agreement. Cleanthes added with nature. Chrysippus explained it as living by our experience of what happens in nature (SEP (opens in a new tab)). Human beings are built to reason and to share a common life, so for us it comes down to thinking clearly and treating people well. See what is Stoicism? and the principle of living according to nature.

Aretē and kakia

Aretē means excellence: whatever makes a thing good at being what it is. In a person it is excellence of character, and the Stoics held that it is the only thing good in itself. Its opposite, kakia or vice, is the only thing bad in itself. They named four main virtues: phronēsis (wisdom), andreia (courage), dikaiosynē (justice) and sōphrosynē (temperance). They also held that whoever truly has one has all four. The four virtues page gives their Latin names and a free exercise, and temperance has a page of its own.

Adiaphora, proēgmena and apoproēgmena

Adiaphora are indifferents: everything that is neither virtue nor vice, including health, money, reputation and life itself. Indifferent does not mean unimportant. Some indifferents are proēgmena, preferred, because it is natural to choose them: health over sickness, enough money over too little. Their opposites are apoproēgmena, dispreferred. You may pursue the preferred ones sensibly. You just can’t become good by having them or bad by losing them. The full explanation, with Chrysippus’s rule for choosing among them, is on preferred indifferents.

Kathēkon and katorthōma

A kathēkon is an appropriate action: the sensible thing to do given who you are and where you stand, such as keeping your word, looking after your health or caring for an aging parent. Cicero put the idea into Latin as officium, duty, the word in the title of his On Duties. Epictetus works it out through the names a person carries, such as son, brother or senator: each name, examined, marks out its own duties (Discourses 2.10; see roles and duties).

A katorthōma is a right action: the same appropriate action done from a fully virtuous character (Internet Encyclopedia of Philosophy (opens in a new tab)). Two people can both drive across town to sit with a sick friend. If one goes from real care and the other to be seen going, the act is the same, and the Stoics would say only the first comes close to right action.

Oikeiōsis

Usually translated appropriation or affinity: the process by which a creature comes to regard something as its own (oikeion, belonging to the household). The Stoics held that every animal is first attached to itself and its own survival (SEP (opens in a new tab)). As reason develops in a human being, the sense of what belongs to you can widen from yourself to family, friends, fellow citizens and finally all people, fellow members of one rational community (IEP (opens in a new tab)).

Epictetus builds a discourse on friendship on the first half of that story. Every creature, he says, cares for nothing more than its own interest. The question is where it locates that interest.

Put the I and the Mine in your body or your possessions, and whoever stands in the way of them, even a brother or a father, becomes an enemy; siblings who stop speaking over an inheritance are the everyday version. Put it in your will, meaning your own judgments and choices, and your interest becomes the same thing as being a faithful friend, child or parent. That is why the same discourse begins by saying that only the wise can really love. Everything turns on “where the I and the Mine are placed” (Discourses 2.22).

Koinōnia and kosmopolitēs

Koinōnia is community or partnership, and koinōnikos, social, is a word Marcus Aurelius returns to again and again. Kosmopolitēs, citizen of the world, is older than the Stoics. Diogenes the Cynic is reported to have given it as his answer when asked where he came from (SEP (opens in a new tab)). Epictetus tells his students the same about themselves, and says a citizen of the world should act as a hand or foot would if it could think, always with the whole body in view (Discourses 2.10). Marcus puts the same idea as a rule for single actions:

His image is political. An act aimed at nothing beyond yourself “is of the nature of a mutiny” (Meditations 9.23), and it splits your own life as well. Quietly keeping information from colleagues so that you stay indispensable may be legal, even shrewd, but on this view it sets you against the body you belong to. See shared humanity.

Sophos and prokoptōn

The sophos is the sage: the ideal person whose every judgment is sound and who therefore acts well every time. The Stoics treated the sage as a standard to measure by, not as someone you are likely to meet. When critics accuse Seneca of living below his own teaching, he concedes the point: he is no wise man, he says, so they should not expect him to match the best, only to beat the worst (On the Happy Life 17).

Everyone else is at best a prokoptōn, one making progress (the subject of Discourses 1.4). In Enchiridion 48 Epictetus lists the signs of progress: blaming no one, praising no one and making no claims about yourself. See the Enchiridion and practice and progress.

Psychology terms

The Stoics had no separate subject called psychology. Their account of the mind sat partly in physics, since they held the soul to be a body, and partly in logic, since impressions and assent are questions of truth. Most Stoic exercises work on these terms.

Hēgemonikon

The ruling part of the soul: the center that receives impressions, assents to them and sets you in motion. Long usually renders it ruling faculty, ruling principle or ruling part. Marcus comes back to it constantly. Someone who wrongs you has not made your ruling faculty worse (Meditations 7.22), and a mind free from passions is a citadel no one can take (Meditations 8.48, quoted under inner freedom).

Prohairesis

Epictetus’s word for the faculty of choice: the part of you that judges, assents, desires and decides. Long translates it will, which is how it appears in the Discourses 2.22 passage above. Epictetus holds that it is the one thing entirely your own. The full entry is on the Epictetus page.

Eph’ hēmin

“Up to us,” or in Long’s English in our power. It is the phrase behind the first line of the Enchiridion: some things are up to us and some are not. Up to us are opinion, impulse, desire and aversion, our own acts. Not up to us are the body, property, reputation and office. The modern name for this division is the dichotomy of control.

Phantasia

An impression: the way something presents itself to the mind before you have decided anything about it. Long’s word is appearance. Impressions arrive on their own; what you do with them is the core of Stoic practice. Epictetus sorts them four ways.

In ordinary life the fourth kind causes most of the trouble: things that are not so and yet appear to be. Your manager’s short reply looks like displeasure and is only a busy afternoon. Epictetus’s remedy for the habit of believing such appearances is practice in the other direction: “oppose to one habit the contrary habit” (Discourses 1.27). The free Anger exercise starts the same way, by separating what happened from the story you added to it.

Synkatathesis

Assent: saying yes to an impression and accepting it as true. For the Stoics, judgments, emotions and actions all pass through assent, which is why it can be up to you even when the impression is not. You can’t stop the thought she’s ignoring me from arriving. You can decline to agree with it until you know more. See objective judgment and Seneca’s three stages.

Katalēpsis

Grasp, or cognition: getting hold of something as it is. A kataleptic impression (phantasia katalēptikē) is one so clear and accurate that it could only have come from what it shows, and the Stoics made it their standard of truth (SEP (opens in a new tab)). How it relates to, and differs from, Marcus’s habit of describing things plainly is explained on objective representation.

Prolēpsis

A preconception: a general notion everyone shares, such as that the good is worth pursuing and that justice is admirable. Long’s word is præcognition. Epictetus says these notions never contradict one another. Disagreement starts when we apply them to particular cases (Discourses 1.22). Two neighbors both believe in fairness and still fight about the fence. Education, for Epictetus, means learning to apply the shared notions well.

Hormē, orexis and ekklisis

Impulse, desire and aversion. Orexis and ekklisis are reaching for what you think is good and turning from what you think is bad. Hormē is the impulse to act, which Long calls movement towards a thing. Together with assent they make up Epictetus’s three areas of training (Discourses 3.2): desire and aversion, impulse and duty, and assent. See the three areas of training.

Oiēsis

Self-conceit: the belief that you already know. Epictetus calls throwing it away the first business of anyone who takes up philosophy, because no one can learn what he thinks he already knows (Discourses 2.17). In ordinary life it is the expert in the meeting who can’t hear a new idea, or anyone who reads a little Stoicism and starts correcting other people.

Pathos

A passion. In the Stoic technical sense, a passion is an excessive impulse resting on a false judgment of value: treating something as truly good or bad when it isn’t. They listed four main kinds: distress over a present evil, fear of a future one, appetite for a future good and pleasure in a present one (SEP (opens in a new tab)). Long sometimes translates the plural pathē as affects or perturbations (Discourses 3.2). Seneca’s account of how anger takes hold is on the three stages of a passion, and his whole treatise is on On Anger.

Apatheia

Freedom from passions in that technical sense. It is not apathy, even though the English word comes from it. The Stoic aim was to be free of the false judgments that produce rage, panic and envy, not to stop feeling. Epictetus says he does not want to be unmoved like a statue; he wants to keep up his relations, natural and acquired, as a son, a father and a citizen (Discourses 3.2). In Enchiridion 12, Long’s freedom from perturbation translates apatheia. Epictetus prices it in small things: when the oil is spilled or a little wine stolen, tell yourself that this is what calm costs. More in not like a statue.

Eupatheiai and propatheiai

The eupatheiai are the good feelings the Stoics kept: joy (chara), caution (eulabeia) and wishing (boulēsis), the reasonable counterparts of pleasure, fear and appetite (IEP (opens in a new tab)). Distress has no good counterpart. The propatheiai are first movements: the flush, the start, the jolt in the stomach, which come before any assent and so are not passions at all. Seneca explains them in On Anger 2.2–4. Both are covered on the good feelings and what training can’t remove.

Ataraxia and euthymia

Ataraxia is freedom from disturbance. The Epicureans made it central to their goal. The Stoics used the word too, but saw calm as a result of virtue, not the aim. In Enchiridion 12 it sits beside apatheia, and Long translates it tranquillity. Euthymia is cheerful steadiness of mind. Seneca says the Greeks call this state euthymia and that his Latin word for it is tranquillitas, the word in the title of his On Tranquility of Mind (chapter 2; Stewart’s English is peace of mind). For the contrast between the two schools, see Stoicism vs. Epicureanism.

Prosochē and askēsis

Attention and training. Prosochē is the steady watch over your own impressions and choices. Epictetus gives it a whole discourse (Discourses 4.12), which opens with a warning: once you let your attention slip, you won’t get it back whenever you like. Askēsis is the training that builds the habit, through exercises chosen to work against your own bad habits, not to draw admiration (Discourses 3.12). Both stand behind the practices.

Physics and theology terms

Stoic physics covers everything that exists, including god, whom the Stoics did not place outside the world. Many modern readers practice the ethics and hold this part loosely; see is Stoicism a religion?

Logos

Reason, and also word or account. In Stoic physics the logos is the rational principle that runs through the whole world and orders it. The Stoics also called it god, Zeus or nature. Every human mind has a share of it, which is why they thought all people are kin. See what the Stoics meant by God.

Physis

Nature, in two senses: the order of the whole world, and the nature of a particular thing, meaning what it is built to do. Living according to nature uses both. You accept the order of the whole, and you act as what you are, a reasoning and social animal. See telos above.

Pneuma

Breath: a warm, fiery breath that the Stoics held runs through all bodies, gives each its qualities and holds it together. It is the physical vehicle of the logos, and the soul is made of it (SEP (opens in a new tab)). Marcus sums himself up as a little flesh, breath and the ruling part (Meditations 2.2).

Heimarmenē and pronoia

Fate and providence. Heimarmenē is the unbroken order of causes in which one thing follows another. Pronoia is the same order seen as rational and caring, arranged for the good of the whole. The practical consequence is in Enchiridion 8: wish for things to happen as they actually happen. See fate and providence and amor fati.

Sympatheia

The interconnection of all things: the cosmos as one living being whose parts affect one another. Marcus tells himself to picture the universe as a single living thing with one substance and one soul (Meditations 4.40), and to keep in mind how all things are bound up with one another (Meditations 6.38). Long’s word in Meditations 4.27 is sympathetic.

Ekpyrōsis

Conflagration: the Stoic theory that the cosmos periodically turns entirely to fire and is then reborn in order (SEP (opens in a new tab)). Marcus mentions Heraclitus’s speculations about it (Meditations 3.3) and the periodic renewal of all things (Meditations 11.1). In the Meditations it serves mostly as a reminder that nothing lasts.

Daimōn

A divinity or guiding spirit. Marcus writes of the daimōn that Zeus has given every person as a guardian and guide, a portion of himself, and then says what it is: each person’s understanding and reason (Meditations 5.27). That is why eudaimonia, having a good daimōn, comes back in the end to having good judgment.

Modern labels

Several of the best-known “Stoic terms” are modern names for ancient ideas. This site uses them and marks them as modern. Here is the ancient wording behind each.

The lowercase adjective stoic, meaning unemotional or uncomplaining, is a modern usage too, and it is the one most often confused with the philosophy. Stoic or stoic sorts out the two words.