Cicero’s reply to Fam.~6.16, written from somewhere in Latium in the middle of April 44 BC — a month after the Ides (Perseus dateline: in Latio medio mense Aprili 710 (44)). Bithynicus had written from Sicily asking Cicero to look after his affairs in his absence, and had closed with a promise that, if the commonwealth could be set right, he would spend his life with Cicero. The reply takes that promise as its hinge.

Cicero answers in the careful, balanced register of an older man receiving the loyalty of a younger one whose father had been his friend. The political background is the new uncertainty after Caesar’s death: “if the commonwealth is at last established” is the wish of the whole spring of 44, and Cicero hangs the rest of the note on it. The closing distinction is the substance of the letter: those who have profited under the times that suited them are bound to Bithynicus by larger obligations than Cicero, but no one is bound to him by closer family ties — the necessitudo of an inherited friendship outweighs the recent debts of fortune. The Latin text as Perseus preserves it breaks off mid-sentence; the manuscript tradition is incomplete at the close.