§11.15.1etsi mihi tuae litterae iucundissimae sunt, tamen iucundius fuit, quod in summa occupatione tua Planco conlegae mandasti ut te mihi per litteras excusaret; quod fecit ille diligenter.
Although your letters are most pleasant to me, yet it was more pleasant that, in your extreme busyness, you charged your colleague Plancus to excuse you to me by letter; which he did diligently.
mihi autem nihil amabilius officio tuo et diligentia.
But to me nothing is more lovable than your kindness and attentiveness.
coniunctio tua cum conlega concordiaque vestra, quae litteris communibus declarata est, senatui populoque Romano gratissima accidit.
Your union with your colleague and your harmony, which was declared in your joint letter, happened to be most welcome to the senate and the Roman people.
§11.15.2quod superest, perge, mi Brute, et iam non cum aliis sed tecum ipse certa.
For the rest, go on, my dear Brutus, and strive now not with others but with yourself.
plura scribere non debeo, praesertim ad te, quo magistro brevitatis uti cogito.
I ought not to write more, especially to you, whom I intend to use as a teacher of brevity.
Litteras tuas vehementer exspecto, et quidem talis qualis maxime opto.
I eagerly await your letters, and indeed of such a kind as I most especially desire.
vale. .
Farewell.