In chapter one of the twelfth book of his Institutio oratoria, Quintilian goes out of his way to defend his meta-rhetorical thesis that only a morally good man can be called an orator. This article argues that, from a logical point of view, his reasoning has many leaks and is ultimately not convincing. What is more, Quintilian seems to have been conscious about the fallaciousness of his own argument. So this article goes on to search for an explanation of his resolution to take upon himself the herculean task to establish the validity of his paradoxical thesis.

As a designation for specific arguments providing clever explanations or excuses in mock-forensic speeches (controversiae), the technical metaphor color is mainly known from the work of Seneca the Elder. But while the many colores he cites lack their speech context, the Major Declamations ascribed to Quintilian give a unique opportunity to study the techniques of “colouring” within the framework of entire speeches. After a reconsideration of what we know about the origin and the exact meaning of color, this article demonstrates the dual function of colores as a means both of generating arguments and of creating stories, i.e. as a device that is rhetorical as well as literary.