The ravages of time is a recurring theme in Shakespeare's sonnets; often it is addressed in terms of its unavoidable effect on beauty and youth, specifically that of the fair lord, but here its effects on statues and monuments is the focus. "Wasteful war," "broils," the sword of Mars (the god of war), and "war's quick fire" are seen as the chief causes of the destruction of statues and monuments, in addition to "sluttish time." Here, "sluttish" means lewd and whorish, and characterizes time as apathetic to the orderliness of the world.
Gonzalo's description of his ideal society (–157, 160–165) thematically and verbally echoes Montaigne 's essay Of the Canibales , translated into English in a version published by John Florio in 1603. Montaigne praises the society of the Caribbean natives: "It is a nation ... that hath no kinde of traffike, no knowledge of Letters, no intelligence of numbers, no name of magistrate, nor of politike superioritie; no use of service, of riches, or of poverty; no contracts, no successions, no dividences, no occupation but idle; no respect of kinred, but common, no apparrell but natural, no manuring of lands, no use of wine, corne, or mettle. The very words that import lying, falsehood, treason, dissimulation, covetousnes, envie, detraction, and pardon, were never heard of amongst them."  In addition, much of Prospero's renunciative speech (–57) echoes a speech by Medea in Ovid 's poem Metamorphoses . 
Though it’s true that Shakespeare’s mockery (however blatant one finds it) of the play’s Christians doesn’t erase its prejudice, “it goes some way toward redressing the moral balance,” notes Marowitz. In other words, by making the Jew look a little less bad, and the Christians look a little less good, Shakespeare is leveling the moral playing field — which is perhaps what the play hints at when Portia, upon entering the courtroom, seems unable to tell the difference between the Christian and his opponent. “Which is the merchant here, and which the Jew?” she asks.