Editing Divine Comedy (section)

== Thematic concerns ==
The ''Divine Comedy'' can be described simply as an [[Allegory in the Middle Ages|allegory]]: each canto, and the episodes therein, can contain many alternative meanings. Dante's allegory, however, is more complex, and, in explaining how to read the poem&nbsp;(see the ''Letter to [[Cangrande I della Scala|Cangrande]]'')<ref>{{cite web |url=http://faculty.georgetown.edu/jod/cangrande.english.html |title=Epistle to Can Grande |work=faculty.georgetown.edu |access-date=20 October 2014 |archive-date=29 January 2015 |archive-url=https://web.archive.org/web/20150129065524/http://faculty.georgetown.edu/jod/cangrande.english.html |url-status=live}}</ref> he outlines other levels of meaning besides the allegory: the historical, the moral, the literal, and the [[anagoge|anagogical]].

The structure of the poem is also quite complex, with mathematical and numerological patterns distributed throughout the work, particularly threes and nines. The poem is often lauded for its particularly human qualities: Dante's skillful delineation of the characters he encounters in Hell, Purgatory, and Paradise; his bitter denunciations of [[Florence|Florentine]] and Italian politics; and his powerful poetic imagination. Dante's use of real characters, according to [[Dorothy Sayers]] in her introduction to her translation of the ''Inferno'', allows Dante the freedom of not having to involve the reader in description, and allows him to "[make] room in his poem for the discussion of a great many subjects of the utmost importance, thus widening its range and increasing its variety."<ref>[[Dorothy L. Sayers]], ''Hell'', Introduction, p.&nbsp;16 (Penguin, 1955).</ref>

Dante called the poem "Comedy" (the adjective "Divine" was added later, in the 16th century) because poems in the ancient world were classified as High ("Tragedy") or Low ("Comedy").<ref>{{cite web |url=http://www.worldhistory.org/Greek_Tragedy/ |title=World History Encyclopedia|access-date = 20 April 2021|archive-date = 21 April 2021|archive-url = https://web.archive.org/web/20210421175335/https://www.worldhistory.org/Greek_Tragedy/|url-status = live}}</ref> Low poems had happy endings and were written in everyday language, whereas High poems treated more serious matters and were written in an elevated style. Dante was one of the first in the Middle Ages to write of a serious subject, the Redemption of humanity, in the low and "vulgar" Italian language and not the Latin one might expect for such a serious topic. [[Boccaccio]]'s account that an early version of the poem was begun by Dante in [[Latin]] is still controversial.<ref>Boccaccio also quotes the initial triplet:"Ultima regna canam fluvido contermina mundo, / spiritibus quae lata patent, quae premia solvunt / pro meritis cuicumque suis". For translation and more, see Guyda Armstrong, [https://web.archive.org/web/20130402195337/http://www.brown.edu/Departments/Italian_Studies/heliotropia/02-02/armstrong.shtml Review] of Giovanni Boccaccio. Life of Dante. J. G. Nichols, trans. London: Hesperus Press, 2002.</ref><ref>{{cite journal |first=Hiram |last=Peri |title=The Original Plan of the Divine Comedy |journal=Journal of the Warburg and Courtauld Institutes |volume=18 |issue=3/4 |year=1955 |pages=189–210 |jstor=750179 |doi=10.2307/750179 |s2cid=244492114}}</ref>

=== Scientific themes ===
Although the ''Divine Comedy'' is primarily a religious poem, discussing sin, virtue, and theology, Dante also discusses several elements of the [[Science in the Middle Ages|science of his day]] (this mixture of science with poetry has received both praise and criticism over the centuries).<ref>Michael Caesar, ''Dante: The Critical Heritage'', Routledge, 1995, pp.&nbsp;288, 383, 412, 631.</ref> The ''Purgatorio'' repeatedly refers to the implications of a [[spherical Earth]], such as the different stars visible in the [[southern hemisphere]], the altered position of the [[sun]], and the various [[time zone]]s of the Earth. For example, at sunset in Purgatory it is midnight at the [[Ebro]], dawn in Jerusalem, and noon on the [[Ganges|River Ganges]]:<ref>[[Dorothy L. Sayers]], ''Purgatory'', notes on p.&nbsp;286.</ref>

{{poemquote|Just as, there where its Maker shed His blood,
the sun shed its first rays, and Ebro lay
beneath high Libra, and the ninth hour's rays

were scorching Ganges' waves; so here, the sun
stood at the point of day's departure when
God's angel{{snd}}happy{{snd}}showed himself to us.<ref>''Purgatorio'', Canto&nbsp;XXVII, lines 1–6, Mandelbaum translation.</ref>}}

Dante travels through the centre of the Earth in the ''Inferno'', and comments on the resulting change in the direction of [[gravity]] in Canto&nbsp;XXXIV (lines 76–120). A little earlier (XXXIII, 102–105), he queries the existence of wind in the frozen inner circle of hell, since it has no temperature differentials.<ref>[[Dorothy L. Sayers]], ''Inferno'', notes on p.&nbsp;284.</ref>

[[File:Divina Commedia Galileo.png|thumb|[[Galileo Galilei]]'s copy of the first [[Gabriele Giolito de' Ferrari|Giolito]] edition of the poem (1555)]]
Inevitably, given its setting, the ''Paradiso'' discusses [[astronomy]] extensively, but in the [[Geocentric model|Ptolemaic]] sense. The ''Paradiso'' also discusses the importance of the [[experiment]]al method in science, with a detailed example in lines 94–105 of Canto&nbsp;II:

{{numbered verses|first=94|
Yet an experiment, were you to try it,
could free you from your cavil and the source
of your arts' course springs from experiment.

Taking three mirrors, place a pair of them
at equal distance from you; set the third
midway between those two, but farther back.

Then, turning toward them, at your back have placed
a light that kindles those three mirrors and
returns to you, reflected by them all.

Although the image in the farthest glass
will be of lesser size, there you will see
that it must match the brightness of the rest.
| ''Paradiso'', Canto II<ref>''Paradiso'', Canto&nbsp;II, lines 94–105, Mandelbaum translation.</ref>}}

A briefer example occurs in Canto XV of the ''Purgatorio'' (lines 16–21), where Dante points out that both theory and experiment confirm that the [[reflection (physics)|angle of incidence is equal to the angle of reflection]]. Other references to science in the ''Paradiso'' include descriptions of [[clock]]work in Canto&nbsp;XXIV (lines 13–18), and [[Thales' theorem]] about triangles in Canto&nbsp;XIII (lines 101–102).

[[Galileo Galilei]] is known to have lectured on the ''Inferno'', and it has been suggested that the poem may have influenced some of Galileo's own ideas regarding mechanics.<ref>{{cite journal |last=Peterson |first=Mark A. |title=Galileo's discovery of scaling laws |journal=American Journal of Physics |url=https://www.mtholyoke.edu/courses/mpeterso/galileo/scaling8.pdf |publisher=American Association of Physics Teachers (AAPT) |volume=70 |issue=6 |year=2002 |issn=0002-9505 |doi=10.1119/1.1475329 |pages=575–580 |arxiv=physics/0110031 |bibcode=2002AmJPh..70..575P |s2cid=16106719 | access-date=6 February 2018 | archive-date=11 April 2021 | archive-url=https://web.archive.org/web/20210411151757/https://www.mtholyoke.edu/courses/mpeterso/galileo/scaling8.pdf | url-status=dead}}</ref>