Cicero, several editions (Perseus Digital Library)

Most of the collection, arrangement, and publication of Cicero’s letters were due to Tiro, the freedman who was his secretary.   The Ancient History Sourcebook at Fordham University noted:

From Cicero’s letters we can gather a picture of how an ambitious Roman gentleman of some inherited wealth took to the legal profession as the regular means of becoming a public figure; of how his fortune might be increased by fees, by legacies from friends, clients, and even complete strangers who thus sought to confer distinction on themselves; of how the governor of a province could become rich in a year; of how the sons of Roman men of wealth gave trouble to their tutors, were sent to Athens, as to a university in our day, and found an allowance of over $4,000 a year insufficient for their extravagances. . . . The period covered by the letters of Cicero is one of the most interesting and momentous in the history of the world, and these letters afford a picture of the chief personages and most important events of that age from the pen of a man who was not only himself in the midst of the conflict, but who was a consummate literary artist.

Lister read this work on 24 April 1664, a common source in early modern education.  As Freyja Cox Jensen has indicated,

the works of Cicero represented the most detailed record of politics, philosophy and intellectual culture in the late Roman republic.  Cicero, in particular, was thought to be very important in the process of assimilation of information from wider reading.  Through reading Cicero, students could gain a deeper understanding of the workings of Rome in the first century BC, and of the actors and issues most important in Rome’s political developments.  ¹

One also wonders if Lister was influenced by Cicero’s literary style, considered a model of Latin Prose writing.  In his own correspondence and published works, Lister cultivated a fluid and clear Latinity.   Lister later donated a 1677 edition of this work to Oxford.