Cicero to M. Junius Brutus, written from Rome — Perseus dateline Scr. Romae iii Non. Mai. a. 711 (43), i.e.\ 5 May 43 BC, the date confirmed by the subscript “iii Nonas Maias” that closes section 4. The dateline matches the meta date. Two weeks have passed since 1.3: the consuls Hirtius and Pansa are dead, Mutina has been relieved, Antony is in flight westward toward Lepidus, Decimus Brutus is north of the Po, and the political problem of the moment is the double vacancy in the consulship and the wider question of where the surviving republican commanders should deploy. Section 1 reports the Senate’s motion of 27 April (a.d. v Kal. Mai.) on the pursuit of those declared hostes: Servilius (the consular P. Servilius Isauricus) proposed that Cassius should hunt down Dolabella in Syria, and that Brutus, in Macedonia, should have his own discretion whether to pursue Dolabella by war or hold his army in place — a compliment, as Cicero notes, of the highest order.

Section 3 is a domestic matter that lights up the politics around it. Cicero’s son, “our Cicero,” is serving on Brutus’s staff in Macedonia; Cicero wants him co-opted into the augural college, on the precedent that absent men can stand. Gaius Marius’s election while in Cappadocia under the Lex Domitia is the precedent adduced; the wording of the more recent Lex Iulia (Caesar’s priesthood law of 46) is cited verbatim, in Cicero’s hand, as decisive. The list of candidates — young Cicero, Domitius, “our Cato” (probably L. Calpurnius Bibulus, Brutus’s stepson, or Brutus’s nephew, M. Porcius Cato the younger) — is the future republican aristocracy under arms in the East; the augurate is the office that formalises their place at home. Section 4 explains why the elections cannot move forward: with both consuls dead and only one patrician magistrate (the praetor urbanus, M. Cornutus) holding the auspices, the formal mechanism of interregnum cannot be triggered. The letter is short, technical, and characteristic Cicero: a national crisis treated through the small constitutional gear-work that keeps the state running.