I still was bent, attentive, over him [Guido da Montefeltro],
when my guide nudged me lightly at the side
and said: "You speak; he is Italian." (Inf. XXVII, 31-33)
Contrary to its role in the previous canto, language here becomes a tool for solidarity and unification under the same nation. Whereas Dante is not allowed to speak to Ulysses because he is Greek, here Virgil urges him to speak to Montefeltro because they use the same language. Thus, language can form a basis of nationalism.
Quote 14
[Virgil]: "For we have reached the place of which I spoke
where you will see the miserable people,
those who have lost the good of the intellect." (Inf. III, 16-18)
Dante considers the mind and reason as purely human faculties and singular gifts from God. Man, then, has a responsibility to use these intellectual gifts for good. Sinners who use their intellects for evil or simply deny that reason is a human tool have "lost the good of the intellect" and have therefore been condemned to Hell.
[Virgil]: "Look well at him who holds that sword in hand,
who moves before the other three as lord.
That shade is Homer, the consummate poet;
the other one is Horace, satirist;
the third is Ovid, and the last is Lucan.
Because each of these spirits shares with me
the name called out before by the lone voice,
they welcome me – and, doing that, do well."
And so I saw the splendid school assembled,
led by the lord of song incomparable,
who like an eagle soars above the rest.
Soon after they had talked a while together,
they turned to me, saluting cordially;
and having witnessed this, my master smiled;
and even greater honor then was mine,
for they invited me to join their ranks –
I was the sixth among such intellects. (Inf. IV, 86-102)
In medieval times, more so than today, poets represented the consummate academics. Dante demonstrates this by referring to the most famous Classical poets as a "splendid school." The character Dante, as an aspiring poet, is flattered when Virgil’s peers invite him to converse with them and he finds himself "sixth among such intellects." If one approaches this statement from the perspective of Dante the author, this rank of "sixth among such intellects" could be read as a bit cocky.