Stoicism

Stoicism is a school of Greek philosophy founded in Athens around 300 BCE by Zeno of Citium, who taught in the Stoa Poikile ("Painted Porch"), from which the school takes its name. Zeno's successors Cleanthes and especially Chrysippus systematized the school's logic, physics, and ethics over the next two centuries, a period known as the Early Stoa. In the 2nd and 1st centuries BCE, Panaetius and Posidonius carried Stoicism to Rome and adapted it for a Roman audience. It was in the Roman imperial period, however, that Stoicism produced the writers whose work survives most completely and who shape its modern reception: Seneca, Epictetus, and Marcus Aurelius. Almost none of the early Greek Stoics' original texts survive intact; they are known largely through fragments and later summaries by writers such as Diogenes Laërtius.

As a philosophical system, Stoicism was traditionally divided into logic, physics, and ethics. Its logic covers reasoning and epistemology, including the criterion of true impressions and what would become propositional logic. Its physics describes a rational, ordered, and deterministic universe governed by logos, a pervasive rational principle running through all things. Its ethics, the part best known today, holds that virtue — wisdom, justice, courage, and temperance — is the only true good, while health, wealth, and reputation are "indifferent," though some indifferents are preferred over others. Central to Stoic practice is the distinction between what is "up to us" (our judgments, desires, and actions) and what is not (external events, other people, and outcomes); tranquility comes from confining one's concern to the former. Stoics held that destructive emotions like fear, grief, and anger arise from mistaken judgments about the value of externals, and that these judgments can be corrected through reasoned reflection. The aim of life, in Stoic terms, is to live in agreement with nature and reason.