Family: the Claudii Severi of Pompeiopolis. Cn. Claudius Severus belongs to the Claudii Severi — a major senatorial family from Pompeiopolis in Paphlagonia (the south-east coast of the Black Sea, in the eastern part of Roman Anatolia). The family received the civitas Romana in the second half of the first century (apparently under the Flavians; the nomen Claudius indicates an original patron from the Claudian house — perhaps Claudius or Nero). By the Antonines the Severi emerge as a wealthy provincial-Hellenic senatorial dynasty: one of the most brilliant examples of the "Hellenisation of the Senate" which Hadrian and the Antonines systematically pursued — alongside such families as the Julii Severi, the Tiberii Julii Celsi, etc.

NB: not to be confused with the Severan dynasty. Cn. Claudius Severus is in no way connected with the later Severan imperial dynasty (Septimius Severus, founder in 193 CE). These are different families, different origins, different periods. The coincidence of the cognomen Severus is etymologically transparent (from severus — "stern"), widely used in the Antonine age without dynastic significance.

Senatorial career. Can be reconstructed only in general outline; the sources are fragmentary.

• Suffect consul — approximately 173; the precise date is disputed, and is fixed by the consular fasti with varying degrees of confidence. Possibly he held office jointly with a colleague from the Severan family line (but not to be confused with the dynasty!).
• In the other parts of the cursus honorum — the standard senatorial path (quaestorship, praetorship), reconstructible by analogy with other members of the family.
• He is not known either as a commander in significant wars or as governor of a major province — which is consistent with his profile as a philosopher-senator, rather than a military-administrative figure.

A kinship connection with the imperial family. A point of principal significance in the elder Severus's biography: his son — Cn. Claudius Severus Arabianus — married Marcus's daughter Annia Galeria Aurelia Faustina (born, on Birley's reconstruction, approximately 151; the marriage in the early 160s). This makes the elder Severus the father-in-law of Marcus's daughter (consocer, or in Greek πενθερός). From this marriage descends the line of the Aurelii Severi, prominent under Commodus and afterwards. This kinship connection is, of course, important for the interpretation of Med. 1.14 (see below on the word ἀδελφοῦ).

Philosophical affiliation: Peripatetic. Severus is a Peripatetic (of the Aristotelian school). This is attested by:

• SHA Marcus (Vita Marci, ch. 3) lists Severus among Marcus's teachers with a direct indication of the school.
• Galen, who was acquainted with Marcus and his circle, mentions Severus as a philosopher in several works (the precise references should be verified against the Kühn edition; Galen was also a doctor of Severus in some episodes, recorded in De praecognitione).

The Peripatetic orientation of Severus is in itself significant in the context of Book I, where the Stoic attribution dominates. With Alexander the Platonist (1.12) and Severus, Marcus has two teachers outside the Stoic school — but from different schools: Middle Platonism and the Peripatetic. This is a deliberate multi-school character of his philosophical education.

The famous textual problem: ἀδελφοῦ or φίλου? The Greek of Med. 1.14 opens with the formula "παρὰ τοῦ ἀδελφοῦ μου Σεουήρου" — "from my brother Severus." This is a problem: Marcus had no biological brothers; his adopted brother and co-ruler — L. Aelius Aurelius Verus (Lucius Verus) — was not "Severus." The English commentator Thomas Gataker in his celebrated edition of the Meditationes (Cambridge 1652) proposed the emendation φίλου ("friend") for ἀδελφοῦ ("brother") — palaeographically plausible (the letters ΦΙΛΟ / ΑΔΕΛΦ in cursive can be confused) and resolving the contradiction: Marcus thanks his "friend Severus," that is, this very Peripatetic-senator.

Alternative approaches not requiring emendation:

1. A metaphorical "brother." The word ἀδελφός could be used in an emphatic-affective sense — "brother in dignity, philosophical brother" — which is not rare in Hellenistic and Roman friendly rhetoric (compare the Latin frater in Ciceronian epistolary formulae to intimate friends).
2. Marriage as affinity. By the probable date of composition of Book I (the second half of the 170s), Severus's son had already married Marcus's daughter — Severus was a relative by affinity, and the word "brother" might reflect this strengthened familial status. This reconstruction is chronologically exact but semantically (in Latin and Greek kinship nomenclature frater / ἀδελφός do not normally cover the relation through the marriage of children) disputed.

The modern consensus (Birley, Hard, Farquharson): the textual problem is not finally settled; the identification Severus = Cn. Claudius Severus, Peripatetic, is accepted by all, regardless of how exactly one qualifies Marcus's relation to him — whether as "brother" (with one or another metaphorical justification) or as "friend" (with the acceptance of Gataker's emendation). Most modern translations retain the reading "brother" with an explanatory footnote — formally observing the manuscript text.

• 01-14 — the only developed portrait of Severus in the Meditations; the source of all we know of his ethical-pedagogical programme.
• 01-17 — the thanksgiving to the gods for "having received good teachers"; Severus is implicitly among them.

• SHA Marcus (Vita Marci), ch. 3 — the catalogue of Marcus's philosophical teachers, where Severus is named as a Peripatetic. Standard text — Hohl, Teubner; the exact sub-paragraph segmentation in ch. 3 should be verified against the edition.
• Galen — mentions Severus as a philosopher and (in some episodes) as a patient; the exact references should be verified against the Kühn edition (especially De praecognitione).
• A. Birley, Marcus Aurelius: A Biography, rev. ed., Routledge, 2000 — the reconstruction of the Claudii Severi family and the marriage connection with the imperial family (ch. 3 "Education" and passim on family alliances).
• A. S. L. Farquharson, The Meditations of the Emperor Marcus Antoninus, Oxford 1944, vol. II, ad 1.14 — the detailed philological commentary, including on the textual problem ἀδελφοῦ / φίλου.
• R. Hard, Marcus Aurelius: Meditations, OWC, Oxford 2011, notes ad 1.14.
• P. Hadot, The Inner Citadel, tr. M. Chase, Harvard 1998 — the general reconstruction of Marcus's tutorial environment (consult the index for "Severus").
• Thomas Gataker, Marci Antonini Imperatoris de Rebus Suis Libri XII, Cambridge 1652 — the editio princeps of the emendation φίλου for ἀδελφοῦ in Med. 1.14.
• PIR² C 1023 — the standard prosopographical entry (the exact entry-number should be verified against PIR²).