First published in 1519 or 1521, the Institutiones Rhetorices was a brief handbook of rhetoric (some 60 small pages). Seel also the more developed rhetoric, Elementorum Rhetorices libri duo (1531).

The Institutiones reflects Melanchthon's immersion in dialectic, a subject upon which he had broadly published. This is evident in the fact that Melanchthon adds Judgment to the conventinoal canons of Invention, Arrangement, and Style.

Invention (a2r-b5r)
The first part of this short book is devoted to invention, where Melanchthon outlines the appropriate parts of an oration and the fitting topics of invention for each of four kinds of cases (Melanchthon adds "dialectical" oratory to the standard three kinds of causes or themes: demonstrative, deliberative, and judicial). He also outlines topics of invention of a more general nature that can be applied in any speech, referring readers to Erasmus's De copia for instruction in employing these, and then explicitly drawing his list of topics from Rudolph Agricola. They include some 60 such general themes as God, Nature, Life, Age, Virtue, Justice, Piety, Lust, Shame Pain, Hope, Anger, Friendship, Truth, War, Peace, Gold, Tyranny, etc.

Arrangement (b5r-b5v)
Mentioned briefly are the standard parts of an oration: exordium, narratio, confirmatio, confutatio, peroratio. These have essentially been dealt with in detail under each of the kinds of cases in the first section on invention.

Style (b5v-d6r)
The balance of this small rhetoric is devoted to style. Melanchthon generally defers to Quintilian and Cicero, and includes the following sections and terms:

Levels of Style ("character orationis") (b6r)
     Sublime
     Humble
     Medium

Ornamentation (b6r-b7v)
     Figures of words (figurae verborum)
     Figures of thought (figurae sententiarum)
Despite opening with this standard two-fold division of figures, Melanchthon proceeds within this section to set forth three separate divisions of figures:

1. Figures of words
2. Figures of discourse
3. Figures of amplification
   These include those figures which "do not so much ornament as they augment" or amplify a discourse (b7r) such as distributio [=Division].

Grammatical Figures (b7v-b8r)
Melanchthon refers to Donatus or the tables of Mosellanus for more information on these figures, but briefly mentions the categories of orthographical or syntactical figures

Tropes (b8r-c1v)
Melanchthon divides tropes into those of words and of discourse (dictionum and orationis)

Schemes