“Gloom as of Hell and night, night that allow’d no planet’s gleam, under a straitened sky, night to the utmost darkened by dense cloud, over my sight ne’er spread a canopy so thick, of frieze so rasping to the sense, as did that smoke we there were covered by”
. . . . .
The smoke on this level of Purgatory symbolizes the way that wrath, or anger, tends to obscure a person’s judgment. Souls stained by this sin must endure literal blindness as a means of purging the sin. Dante asks explain why the world is so filled with wrongdoing—is the cause in “the stars” or elsewhere? although people tend to believe that everything’s caused by the stars, this isn’t true—if it were, that would destroy the freedom of the human will, and it wouldn’t be fair for souls to be either rewarded or punished. “The stars” might initiate human behavior, but humans are given “light” to discern between good and bad, and “free will” which, when shaped well, can guide behavior accordingly.