Modern editors divide the Epistle into thirty-three paragraphs or chapters. These fall into three main sub-sections: paragraphs 1–4 dedicate the Paradiso to Can Grande; paragraphs 5–16 begin by presenting a general introductory discussion of allegory with reference to the four interpretative ‘senses’ of biblical exegesis (§7), and then analyse the Commedia as a whole and the third cantica in particular under six headings drawn from one of the standard models of academic prologue to an auctor (‘There are six parts … which need to be discussed at the beginning of every didactic work, namely, the subject, the author, the form, the aim, the book's title, and the branch of philosophy to which it belongs'; §6); finally, paragraphs 17–33 offer a close ‘literal’ reading of the opening twelve lines of Paradiso, concentrating in particular and with considerable expertise on many of their philosophical and theological allusions.

One of the most controversial issues in present-day Dante studies concerns the authorship and significance of the Epistle to Can Grande, whose apparent addressee was the Lord of Verona between 1311 and 1329. Unlike most other critical disputes, the question of whether the letter is or is not by the poet has a direct and fundamental bearing upon our appreciation of the Commedia and of its author's intellectual development. If genuine, then, the Epistle is a key auto-commentary to the poem, second only in importance to the Commedia's own self-reflexive critical system, although any comparison between them confirms the undoubted greater exegetical range and sophistication of the poem.