Quintilian, and J.S. Watson. Institutes of Oratory. Edited by Lee Honeycutt, 2010. Kindle Electronic Edition. Book 12 Chapter 7.
In book 12 chapter 7 Quintilian moves to the best work for a young orator. He recommends working in defense before prosecution (Quintilian XII.7.1). Defending people appropriately but allowing justice to operate against the guilty is an important public service (Quintilian XII.7.2). The good orator will consider the character and case of those who would bring cases. He should pursue justice in just causes (Quintilian XII.7.6). He can and should receive payment (Quintilian XII.7.9). However, he should not be seen as a profiteer.