The heaven of Mars is a long heaven, comprising the last section of Paradiso 14, and then Paradiso 15, 16, 17, and the first half of canto 18. The transition to Jupiter occurs in Paradiso 18.61-62. It is not quite as long as the heaven of the sun: the heaven of the sun comprises four complete canti and about two-thirds of a fifth canto, while the heaven of Mars comprises three complete canti, about one-third of canto 14 and one-third of canto 18.
The heaven of Mars is the heaven of personal affect and personal history. Looking at Beatrice, Dante feels that he has reached the extreme “of my glory and of my paradise”:
ché dentro a li occhi suoi ardeva un riso tal, ch’io pensai co’ miei toccar lo fondo de la mia gloria e del mio paradiso. (Par. 15.34-36)
for in the smile that glowed within her eyes, I thought that I—with mine—had touched the height of both my blessedness and paradise.
The heaven of Mars is prefaced by the discussion of the resurrected body in the first part of Paradiso 14 (still in the heaven of the sun), a discussion that leads the souls to exclaim “Amen” in joy at the thought that they will get their bodies back. In fact, they experience “disio de’ corpi morti” (Par. 14.63), a desire for their dead bodies that is not just for themselves but for their beloveds:
forse non pur per lor, ma per le mamme, per li padri e per li altri che fuor cari anzi che fosser sempiterne fiamme. (Par. 14.64-66)
not only for themselves, perhaps, but for their mothers, fathers, and for others dear to them before they were eternal flames.
The mothers and fathers desired by the souls of Paradiso 14.64-65 are historicized in the heaven of Mars, where they are the mothers and fathers of Florence, and where Dante meets his own great-great-grandfather.
Dante’s paternal ancestor, Cacciaguida (we learn in Par. 16.34-39 that he was born in 1091), is described in a simile where his affection is compared to that of Anchises, father of Aeneas, on greeting his son:
Sì pia l’ombra d’Anchise si porse, se fede merta nostra maggior musa, quando in Eliso del figlio s’accorse. (Par. 15.25-27)
With such affection did Anchises' shade reach out (if we may trust our greatest muse) when in Elysium he saw his son.
We note the stipulation of verse 26: “if we may trust our greatest muse” refers to the description offered by Vergil and the poetry of the Aeneid (“nostra maggior musa”) of the affectionate encounter between Anchises and Aeneas in Book 6 of the Aeneid. This verse constitutes the first, albeit indirect, reference to Vergil in the poem since the disappearance of Virgilio in Purgatorio 30. In Purgatorio 30, in recounting the moment of his loss, Dante-poet refers to the Latin poet as “Virgilio dolcissimo patre” (Virgilio sweetest father [Purg.30.50]). Thus, true to the dialectical terza-rima texture of this poem, ever spiraling forward and back, the arrival of a new father, Cacciaguida, elicits from Dante the memory of the father whom he has lost.
The heaven of Mars is the heaven of the bloodline, of the lineage, of ancestry, of the family root and tree. Cacciaguida’s first words to Dante are “o sanguis meus”—“O blood of mine” (Par. 15.28)—and canto 16 begins with Dante’s celebration of his family lineage, his “nobiltà di sangue” (nobility of blood [Par. 16.1]).
Cacciaguida explains Dante’s family to him, where he fits into the lineage and who he, Cacciaguida, is in relation to the pilgrim:
Poscia mi disse: «Quel da cui si dice tua cognazione e che cent’anni e piùe girato ha ’l monte in la prima cornice, mio figlio fu e tuo bisavol fue: ben si convien che la lunga fatica tu li raccorci con l’opere tue.» (Par. 15.91-96)
then said: “The man who gave your family its name, who for a century and more has circled the first ledge of Purgatory, was son to me and was your great-grandfather; it is indeed appropriate for you to shorten his long toil with your good works.”
The above verses showcase Dante’s genial method of buttressing important moments by using the fictional truth of the text itself, supporting textual reality with more textual reality. Here Cacciaguida tells the pilgrim that his son, Dante’s great-grandfather, is still circling the first ledge of purgatory, the terrace of pride. Cacciaguida thus lets his descendant know that pride is a family trait: we remember the pilgrim’s stated fear (in Purgatorio 14) that he will be spending much time on the terrace of pride when he returns to purgatory.
A lot of affect enters the Paradiso when we enter the heaven of Mars. We are plunged into a world of human feeling and human history: when Dante meets his ancestor Cacciaguida, the conversation becomes very personal, both about Dante’s family and about Florence, a place that elicits great passion from our poet throughout the Commedia.
In Paradiso 15 Cacciaguida paints for his descendant the picture of the idyllic Florence of old in which he, Cacciaguida, lived, before Florentine society was overtaken by decay and corruption. Dante’s description of an earlier Florence is full of real history, and at the same time it is an idealized vision of the city when it was pure and at peace:
Fiorenza dentro da la cerchia antica, ond'ella toglie ancora e terza e nona, si stava in pace, sobria e pudica.
Florence, within her ancient ring of walls— that ring from which she still draws tierce and nones— sober and chaste, lived in tranquility.
In a patrilineal and honor-based society like that of Dante’s Florence, the honor of the society is measured by the comportment of its women. Here the city is gendered female, and the chastity and sobriety of Cacciaguida’s “Fiorenza” contrasts with the current sordid scene, where all facets of female behavior are without misura (a word whose importance as a social barometer we remember from another discussion of Florentine corruption, in Inferno 16). In today’s Florence, there is no misura in female dress, and there is no misura in female dowry requirements, which bankrupt contemporary Florentine fathers:
Non avea catenella, non corona, non gonne contigiate, non cintura che fosse a veder più che la persona. Non faceva, nascendo, ancor paura la figlia al padre, che ’l tempo e la dote non fuggien quinci e quindi la misura. (Par. 15.100-05)
No necklace and no coronal were there, and no embroidered gowns; there was no girdle that caught the eye more than the one who wore it. No daughter’s birth brought fear unto her father, for age and dowry then did not imbalance— to this side and to that—the proper measure.
The war in which Dante’s ancestor Cacciaguida participated was not with his fellow citizens in the kind of factional strife that plagued Florence in Dante’s lifetime (and that caused him to be exiled from Florence). From Dante’s perspective, Cacciaguida fought in an honorable cause and acquitted himself well: he became a knight under the emperor Conrad III, and was killed in the Second Crusade. Thus, Cacciaguida was a Crusader, and the end of Paradiso 15 offers the most conventional medieval Christian anti-Muslim rhetoric that you will find in the Commedia.
Chapter 10 of The Undivine Comedy, “The Sacred Poem Is Forced to Jump: Closure and the Poetics of Enjambment,” analyzes the latter half of Paradiso from a meta-narrative perspective. Paradiso 15 offers a foundational passage in this regard, verses that provide a philosophical key to reading Paradiso. In answer to Cacciaguida’s exhortation to sound forth his will and his desire (in other words, to speak), Dante replies by explaining the diegetic problems—problems of disequality and difference—that beset all mortals:
Poi cominciai così: «L'affetto e ’l senno, come la prima equalità v’apparse, d’un peso per ciascun di voi si fenno, però che ’l sol che v’allumò e arse, col caldo e con la luce è sì iguali, che tutte simiglianze sono scarse. Ma voglia e argomento ne’ mortali, per la cagion ch’a voi è manifesta, diversamente son pennuti in ali; ond’io, che son mortal, mi sento in questa disagguaglianza, e però non ringrazio se non col core a la paterna festa. (Par. 15.73-84)
Then I began: “As soon as you beheld the First Equality, both intellect and love weighed equally for each of you, because the Sun that brought you light and heat possesses heat and light so equally that no thing matches His equality; whereas in mortals, word and sentiment— to you, the cause of this is evident— are wings whose featherings are disparate. I—mortal—feel this inequality; thus, it is only with my heart that I can offer thanks for your paternal greeting.
As I write in The Undivine Comedy:
The pilgrim cannot express his thanks because he is mortal and, being mortal, a creature of difference; never (in a typically Dantesque move) have the disadvantages of mortality been more stunningly expressed than in the simplicity of “ond’io, che son mortal” followed by the enjambment that isolates and highlights the word that forms a hemistich, the magnificently protracted “disagguaglianza”. (p. 219)
This passage tells us clearly that mortality is “disagguaglianza” (Par. 15.83), disequality, while God / paradise / transcendence are divine Equality: “la prima equalità” (Par. 15.74).
And yet, this is very much the story of the latter half of Paradiso: the poet is empowered by the very disagguaglianza that is forsworn by the pilgrim. Equality, in the linguistic sphere, is silence. Language (poetic life) is disequality; language (poetic life) is difference:
What obtains for the pilgrim within the possible world of paradise is, as is frequently the case on Dante’s circular scales, precisely the opposite of what obtains for the poet within the reality of praxis and the written poem: while the pilgrim is blocked by his disequality, the poet is empowered by the very disagguaglianza that he must, in the third canticle, nonetheless forswear. As the poem heads toward the uguaglianza of its ending, as it is deprived of the fuel of disagguaglianza, it stutters; early instances of such stuttering are the first sets of “Cristo” rhymes, located in the life of Dominic in Paradiso 12 and in the passage, toward the end of Paradiso 14, relating the miraculous appearance of Christ within the cross of Mars. These triple rhymes of Cristo / Cristo / Cristo signify not only the incommensurability of Christ to anything other than himself but also the inevitable death of terza rima; as difference in the form of three different rhymes gives way to identity, homology, and stasis, the poem begins to die.
(The Undivine Comedy, p. 219)