Origin. Plutarch was born around 45 CE at Chaeronea — a small town in Boeotia, famous for the battlefield of 338 BCE (Philip II and Alexander against the Greek coalition). His family was local aristocracy with a philosophical-literary tradition; his brother Lamprias and his sons Autobulus and Plutarch the younger appear as interlocutors in his own dialogues. Plutarch himself lived almost his whole life in Chaeronea, travelling only two or three times to Rome and Alexandria.

Education. He studied at Athens under the Platonist Ammonius (exact dates unknown), under whose influence his Platonist school-allegiance was formed. As was customary in the period, he also took up Stoic, Peripatetic, and Epicurean themes — which makes his philosophy eclectic-Platonist, typical of the Middle Academy of the first and second centuries (so-called Middle Platonism).

Position at Delphi. For several decades he served as priest of Apollo at Delphi — an office combining religious, philosophical, and civic standing, and giving a platform for conversations with visiting philosophers. Several of the Moralia dialogues are set at Delphi (De Pythiae oraculis, De E apud Delphos, De defectu oraculorum).

Relations with Rome. Plutarch received Roman citizenship (his tria nomina — Mestrius Plutarchus), was acquainted with senators and, on one version, held an honorary procuratorship of Achaea under Hadrian. But he lived in Greece, not in Rome — which distinguishes him from the Roman philosophers of the Antonine circle (Seneca, Epictetus, Musonius Rufus), and makes him a figure precisely of Greek-provincial intellectual life.

Corpus. Two large groups of writings survive:

• The Parallel Lives (Βίοι Παράλληλοι): about 23 pairs plus 4 separate biographies — a Greek and a Roman hero paired, with an ethical comparison (σύγκρισις). Of these Lives, Marcus in Book I draws directly on Cato Minor, Dion, and Brutus for the canon of Stoic opposition (see 01-14).
• The Moralia (Ἠθικά / Moralia): a collection of some 78 essays and dialogues on ethical, rhetorical, philosophical, antiquarian, and popular-scientific themes. The parallels to Book I:
• De curiositate — the canonical treatment of ἀπραγμοσύνη, background to 01-05 on the τροφεύς.
• De superstitione — the Stoic critique of δεισιδαιμονία, background to 01-06 on Diognetus's scepticism.
• De fraterno amore, De amicorum multitudine — on friendship, background to 01-09 on Sextus.
• Quomodo adulator ab amico internoscatur — on the difference between friend and flatterer, background to 01-07 on the παρρησία of Junius Rusticus.

Connection with Marcus Aurelius

Through Sextus of Chaeronea. Marcus had no direct personal acquaintance with Plutarch: Plutarch died around 125, when Marcus was about four years old. But Sextus, Plutarch's nephew (son of one of his brothers or a nephew in the wider sense; the exact kinship cannot be reconstructed unambiguously from the sources), was one of Marcus's principal philosophical teachers in his mature years. Through Sextus Marcus indirectly inherited a share of the Chaeronean intellectual milieu: the family house of Plutarch, his philosophical academy at Chaeronea, his network of pupils and nephews.

The eclectic-moral register. Plutarch was a Platonist by school-affiliation, but his Moralia and Lives are compatible with the Stoic ethics of Marcus in their practical register. This explains why Marcus in 01-09 describes Sextus as a Stoic, yet admits into his portrait Platonist-moralist tones (παράδειγμα οἴκου, εὐμενές, πάντας εὐάρμοστον). Sextus is a Stoic with the Platonist pedagogical baggage inherited from the Chaeronean circle of Plutarch.

The canon of opposition in 01-14. When Marcus in 01-14 enumerates "Thrasea, Helvidius, Cato, Dion, Brutus" as the five-fold ethical exemplars of resistance to tyranny, three of the five are the heroes of separate Plutarchan Lives (Cato Minor, Dion, Brutus). This is not accidental: the canon of opposition, in the form in which Marcus inherits it, is shaped by the Plutarchan choice of figures. Severus transmitted the canon to Marcus, but the canon itself rests on the Plutarchan biographies as its standard source-texts.

• 01-09 — Sextus as the nephew of Plutarch; through Sextus, the indirect channel of Plutarchan influence.
• 01-14 — the canon of opposition (Cato, Dion, Brutus) resting on the Plutarchan Lives.
• In the parallels to 01-05, 01-06, 01-07, 01-09 — separate works of the Moralia as background texts for the relevant ethical themes.

• Plutarchus, Vitae Parallelae and Moralia — Teubner edition is standard; Russian translations of the Lives in the "Литературные памятники" series (Losev and others), the Moralia partially, by various translators.
• D. A. Russell, Plutarch, London 1973 (a brief introduction).
• C. P. Jones, Plutarch and Rome, Oxford 1971 — the standard monograph on Plutarch's Roman connections.
• T. Duff, Plutarch's Lives: Exploring Virtue and Vice, Oxford 1999 — on the ethical frame of the Lives.
• Cambridge Companion to Plutarch, ed. F. B. Titchener and A. Zadorojnyi, Cambridge 2022 — the current overview volume.