Commentary Inf II 1-6

Against the common opinion (as it exists even today, most recently exhibited by Merc.1998.1) that the two prolusory cantos should be regarded as having separate functions (e.g., I = prologue to the poem as a whole, II = prologue to the first cantica) Wilkins (Wilk.1926.1) argues, on the basis of discussion of the defining characteristics of prologues found in the Epistle to Cangrande (Epist.XIII.43-48), that cantos I and II form a unitary prologue to the entire poem as well as to its first canticle. This reader finds his comments just and convincing. Once again we observe that commentators, following earlier commentators rather than the text of the poem, create interpretive artifacts (here, the notion that the two cantos have separate functions) that then take on, by virtue of repetition, the appearance of being Dantean 'facts.' In actuality, all three cantiche begin with two-canto-long prologues containing an invocation, some narrated action, and presentation of details that prepare the reader for what is to follow further along in the poem. For instance, Inferno I and II look forward to Purgatory and Paradise (e.g., [Inf I 118-129]; [Inf II 71-74]), while Purgatorio I anticipates the ascent to heaven of the saved souls ([Purg I 6]) as well as the general resurrection ([Purg I 75]).

For the structural parallels that also tend to merge the two cantos into a single entity see Holl.1990.2, p. 97:

Inferno I Inferno II
1-27 Dante's peril 1-42 Dante's uncertainty
simile(22-27) simile(37-40)
28-60 three beasts 43-126 three blessed ladies
simile(55-58) simile(127-130)
61-136 Virgil's assurances 127-142 Dante's will firmed