Reference Edition: 

Iulii Severiani, Praecepta artis rhetoricae summatim collecta de multis ac syntomata, introduzione, edizione critica e traduzione italiana a cura di Anna Luisa Castelli Montanari, Bologna 1995.

The title itself indicates that the Praecepta artis rhetoricae summatim collecta de multis ac syntomata are presented as a work for practical use, in schools and as preparatory text for the practice of law (Castelli Montanari). Rather than an original treatise, it is in fact a compendium of rules drawn from auctoritates of the past. In the introduction, Julius Severianus openly states that he has not made any addition to the precepts he has excerpted from the ancients; they have been merely collected, often in abbreviated form (in quasdam sermonis angustias coartasse). The main source is of course Cicero. Quotes are rarely correct: they are expanded or modified to suit the suggested topic better. The work, conceived in its structure as a small handbook of rhetorical exercise, is divided into chapters of various sizes, each of which addresses an issue related to the exercise of rhetoric, starting from the definition of the ars and ending with epilogues. The treatise, in accordance with its nature as a schoolbook, ends exhorting readers to constant practice, without which even the knowledge of all the precepts listed in the book will be useless if not harmful. [A. Borgna; trad. L. Battezzato]