Stoic School of Ancient Greek Philosophy Texts

Stoicism was founded around 300 BCE by Zeno of Citium (c. 334–262 BCE), who taught at the Stoa Poikile, the painted porch in Athens, from which the school takes its name. Zeno had studied with the Cynic Crates and was formed by Socratic literature and the other Athenian schools before beginning his own teaching.

Stoic philosophy was built in three connected parts, λογική, φυσική, and ἠθική. The first, logic, covered the rules of correct reasoning together with the account of knowledge, and it held that all knowledge begins from sense impressions, φαντασίαι. Assent (συγκατάθεσις) is given to impressions that represent things as they are, and such a graspable impression is called καταληπτική φαντασία. The second part, physics, treated the cosmos as a single living thing with its own rationality, composed of two principles: an active principle, identified with λόγος and sometimes called god, and a passive principle, matter in itself without mark. The active principle is a πνεῦμα, a breath that pervades all things, ordering matter and steering all that comes to pass; this ordering is εἱμαρμένη, and the school's word for the divine governance of the whole is πρόνοια. The cosmos runs in eternal cycles, each ending in ἐκπύρωσις, a conflagration in which everything is taken back into the active principle before a new cosmos begins.

The third part, ethics, set the goal of life as εὐδαιμονία, attained by living in agreement with nature (ὁμολογουμένως τῇ φύσει ζῆν): in agreement with one's own rational nature and with the rational nature of the cosmos as a whole. The only true good is ἀρετή, excellence of character shown in practical wisdom, courage, moderation, and justice; everything else, health, wealth, and reputation among them, is indifferent, though some indifferents are naturally preferred. Happiness lies in attending to what is within one's power, one's own judgements, impulses, and commitments (προαίρεσις). The ideal is the sage, who keeps an unimpeded flow of life (εὔροια βίου) and is free from excessive and misplaced impulses, the πάθη.

Zeno's successors as heads were Cleanthes (c. 330–230 BCE), who defended the school's doctrines, and Chrysippus (c. 279–206 BCE), a prolific systematiser who built up Stoic logic and restated its positions in detail. From the 2nd century BCE the centre of activity shifted to Rome: Panaetius (c. 185–110 BCE) and Posidonius (c. 135–51 BCE), the main figures of the Middle Stoa, engaged with Platonic and Aristotelian ideas and took up questions of political and cultural concern. The Roman Imperial period (1st–2nd century CE) produced the Stoic writings most widely read today. Seneca (c. 4 BCE–65 CE), Musonius Rufus (c. 20–100 CE), Epictetus (c. 50–135 CE), and Marcus Aurelius (121–180 CE) wrote mostly in Latin and pressed Stoic ethics into practical service for the conduct of life, duty, and adversity.

The early school, from Zeno through Chrysippus, was centred in Athens and occupied itself with building and defending a complete system against the attacks of the Academy and the Epicureans. In 529 CE imperial edict restricted the teaching of pagan philosophy at Athens, by which time Stoic ideas had already passed into other traditions.