Reference edition:

Rhetores Latini Minores, ex codicibus maximam partem primum adhibitis emendabat Carolus Halm, Lipsiae 1863, 567-570 (Bibliotheca Scriptorum Graecorum et Romanorum Teubneriana).

Ever since Volkmann 1869, a majority of scholars have considered this chapter (567.3-570.22 Halm), as well as the one that follows it, to be sections related to the types of oratory according to Aristotle’s division, rather than of the progymnasmatic type.  Pirovano 2008 nevertheless attempted to show that this section could also be attributed to progymnasmatic literature on the grounds that it defines the demonstrativa materia as a species exercitationis that is distinct, in a strict sense, from the epideictic genre.  If this is correct, the exercise functions as an introduction to the encomium, and it consequently remains possible to attribute the Praeceptum to Emporius. 

The chapter contains a treatment of the genus demonstrativum, which includes both praise and blame, as well as an explanation of how it differs from the locus communis.  It then provides a definition of encomium, enumerates attributes that are able to be praised according to a tripartite temporal sequence (past, present, future), and treats the epideictic typologies not included in the demonstrativa materia (i.e. praise of cities, laudes deorum, natural elements).  [A. Balbo; tr. C. L. Caterine].