anxiety (Discourses 2.13.1). Our judgments about what is up to us determine our freedom (3.26.34–
35).
Epistêmê (ἐπιστήμη): certain and true knowledge, over and above that of katalêpsis.
Ethos (ἔθος): custom or habit. See also hexis. In late Stoic practice, there is a great focus on habit.
Musonius Rufus’s ideas about education were aimed at addressing the upbringing, environment, and
habits that vary from person to person (Lectures 1.1). Epictetus carries this focus on habit forward:
“Since habit is such a powerful influence, and we’re used to pursuing our impulses to gain and avoid
outside our own choice, we should set a contrary habit against that, and where appearances are really
slippery, use the counterforce of our training” (Discourses 3.12.6). He also talks about the importance
of using a contrary, opposing habit in 1.27.4. The term appears seventeen times in Epictetus’s
Discourses. Marcus uses this term four times.
Eudaimonia (εὐδαιμονία): happiness, flourishing, well-being. Epictetus says that God made
human beings to be happy and stable/serene (εὐσταθεῖν/eustathein; Discourses 3.24.2b–3).
Eudaimonia appears thirteen times in the Discourses and once in the Enchiridion. Epictetus holds
that it is incompatible with yearning for what we don’t have (Discourses 3.24.17). It appears twice in
Marcus (7.67) in conjunction with “life,” which, he says, depends on the fewest possible things (see
also 7.17). Marcus has one other equivalent word in his use of εὐζωήσεις/euzôêseis, or “happy in
life” (3.12; none of these three reproduced here).
Eupatheia (εὐπάθεια): good passions or emotions (as contrasted with pathos), the result of
correct judgments and virtuous actions. Diogenes Laertius says, “The Stoics assert there are three
good emotional states (eupatheia): joy, caution, and wishing... joy is rational elation... caution is
rational avoidance.. .wishing is rational inclination.. .under wishing they place goodwill,
benevolence, friendliness and affection; under caution, respect and modesty; under joy, delight, good
cheer and contentment” (Lives of the Eminent Philosophers 7.116).
Hamartanô (ἁμαρτάνω): to do wrong, err, fail one’s purpose. The verb appears twenty-eight
times in Epictetus and thirty-four times in Marcus. Also, hamartia (ἁμαρτία)—a failure, fault, error,
to do wrong to another—appears three times in Marcus, notably in 10.30, when he talks about seeing
another’s wrongdoing from the standpoint of our own failings. Both Epictetus and Musonius Rufus
often use the obverse as the ideal, being free from error, anamartêtos (ἀναμάρτητος), which,
although not possible, is what we should strive for (see especially Discourses 4.12.19; Lectures
2.5.1). Since Aristotle’s Poetics, the concept had been the fatal flaw or decision that leads to a tragic
demise. The Stoics part ways with any tragic thinking, on the one hand, and, on the other, with any
notion of original sin—all sin is the result of bad habit, following common opinion, and bad
judgments. Philosophy is meant to help us scrape the accumulated errors of existence from our souls.
Hêgemonikon (ἡγεμονικόν): ruling or guiding reason; ruling principle. A. A. Long says the term,
meaning “suited to command,” was borrowed from Isocrates, the Athenian rhetorician, and was taken
up by the early Stoics to represent the intellectual part of the soul as distinct from the senses (Greek
Models of Mind and Self, p. 89). Long notes that by the time of the late Stoics, Epictetus had applied
it even to the souls of animals, which lack rationality (Epictetus: A Stoic and Socratic Guide to Life,
p. 211), and said it means “the governing faculty of the mind.” Hadot calls it the superior or guiding
part of the soul. Marcus uses it as a unique property of human beings (especially in 12.1 and 12.33).
Epictetus’s Discourses (twenty-six references): 1.26.15, 1.20.11, 4.4.43, 4.5.5. Marcus Aurelius
(forty-six references): 3.9, 4.38, 5.11, 8.48, 8.56, 9.22, 9.26, 12.1, 12.33. Whereas Epictetus leans
heavily on prohairesis, Marcus prefers hêgemonikon: “How does your ruling reason manage itself?