1. The earliest of these is _De Inventione_, or _Rhetorica_, in two Books, written probably for the author's own use during Sulla's absence in Asia B.C. 87-83. In his mature years Cicero looked back with contempt on this youthful effort: _de Or._ i. 5, 'quae pueris aut adulescentulis nobis ex commentariolis nostris incohata ac rudia exciderunt.' He borrows much from the _Rhet. ad Herenn._, and frequently mentions and criticises the views of Hermagoras; but all the best writers on rhetoric were laid under contribution: ii. 4, 'omnibus unum in locum coactis scriptoribus, quod quisque commodissime praecipere videbatur, excerpsimus.'
2. The three Books _De Oratore_ were finished in 55: _ad Att._ iv. 13, 2, 'de libris oratoriis factum est a me diligenter: diu multumque in manibus fuerunt: describas licet.' They were written at a time when Cicero's voice was seldom heard: _ad Fam._ i. 9, 23, 'ab orationibus diiungo me fere referoque ad mansuetiores Musas.' The dialogue takes place in B.C. 91, at the Tusculan villa of L. Licinius Crassus; he and the rival orator, M. Antonius, are the chief speakers.
3. The dialogue _Brutus_, or _De Claris Oratoribus_, after a brief survey of Greek oratory, criticises the Roman orators from L. Brutus to Cicero's own time. In spite of his intention to omit living persons (§ 231), he discusses Caesar, M. Marcellus, and himself. The speakers are Brutus, Atticus, and Cicero; and the date is probably 46, for the _Brutus_ is earlier than the _Orator_, which refers to it (§ 23).
4. The _Orator_ or _De Optimo Genere Dicendi_ is a sequel to the _De Oratore_ and the _Brutus_, adding practical rules to the exposition of theory (_de Div._ ii. 4). It was written at the request of Brutus, to whom it is addressed, in the year 46 (_ad Fam._ xii. 17, 2).
5. _Partitiones Oratoriae_ is a catechism on rhetoric, in which the questions are put to Cicero by his son.
6. The _Topica_ was written in response to repeated requests from Trebatius for explanation of Aristotle's _Topics_. It was done by Cicero, without the aid of books, on his voyage from Velia to Rhegium in July, 44 (_Top._ 5; _ad Fam._ vii. 19).
7. The short treatise _De Optimo Genere Oratorum_ was introductory to a version of the speeches of Demosthenes and Aeschines 'on the Crown,' designed to show the Romans what the best Attic oratory was like.