Dio Chrysostom, On Training for Public Speaking 2

So let us consider the poets: I would counsel you to read Menander of the writers of Comedy quite carefully, and Euripides of the writers of Tragedy, and to do so, not casually by reading them to yourself, but by having them read to you by others, preferably by men who know how to render the lines pleasurably, but at any rate so as not to offend. For the effect is enhanced when one is relieved of the preoccupation of reading. 

And let no one of the more "advanced" critics chide me for selecting Menander's plays in preference to the Old Comedy, or Euripides in preference to the earlier writers of Tragedy. For physicians do not prescribe the most costly diet for their patients, but that which is salutary. 

Now it would be a long task to enumerate all the advantages to be derived from these writers; indeed, not only has Menander's portrayal of every character and every charming trait surpassed all the skill of the early writers of Comedy, but the suavity and plausibility of Euripides, while perhaps not completely attaining to the grandeur of the tragic poet's⁠ way of deifying his characters, or to his high dignity, are very useful for the man in public life; and furthermore, he cleverly fills his plays with an abundance of characters and moving incidents, and strews them with maxims useful on all occasions, since he was not without acquaintance with philosophy. 

But Homer comes first and in the middle and last, in that he gives of himself to every boy and adult and old man just as much as each of them can take. 

Lyric and elegiac poetry too, and iambics and dithyrambs are very valuable for the man of leisure, but the man who intends to have a public career and at the same time to increase the scope of his activities and the effectiveness of his oratory, will have no time for them. 

But the historians for many reasons the statesman must read attentively, because, even apart from the speeches they contain, it is most essential that the statesman, the man who chooses to conduct public affairs, should be acquainted with measures and successes and failures, which happen not only in accordance with reasonable expectation, but also at times contrary thereto, to both men and states. 

And the reason for this statement is that it is the man with the widest knowledge of what had happened to others who will best carry out his own undertakings, and, so far as it is possible, safely, while every reverse he will bear nobly because of the fact that even in his successes he was never unaware of the possibility of a change to the opposite fortune. 

As for Herodotus, if you ever want real enjoyment, you will read him when quite at your ease, for the easy-going manner and charm of his narrative will give the impression that his work deals with stories rather than with actual history. 

But among the foremost historians I place Thucydides, and among those of second rank Theopompus;⁠ for not only is there a rhetorical quality in the narrative portion of his speeches, but he is not without eloquence nor negligent in expression, and the slovenliness of his diction is not so bad as to offend you. 

As for Ephorus,⁠ while he hands down to us a great deal of information about events, yet the tediousness and carelessness of his narrative style would not suit your purpose.