Quintilian Institutio Oratoria 10.1.23

[23] And even if such speeches seem unequal in point of merit, we shall still do well to study them carefully with a view to understanding the problems raised by the cases with which they deal: for example, we should compare the speeches delivered by Tubero against Ligarius and by Hortensius in defence of Verres with those of Cicero for the opposite side, while it will also be useful to know how different orators pleaded the same case. For example, Calidius ¹ spoke on the subject of Cicero's house, Brutus wrote a declamation in defence of Milo, which Cornelius Celsus wrongly believes to have been actually delivered in court, ² and Pollio and Messalla defended the same clients, ³ while in my boyhood remarkable speeches delivered by Domitius Afer, ⁴ Crispus Passienus ⁵ and Decimis Laelius ⁶ in defence of Volusenus were in circulation.