The Irony of Weston's Eloquence
Dr. Weston is a self-assured, confident, and rhetorically capable man who asserts his ideas with vigor and stubbornness. He is grandiloquent when communicating his ideas in English to Ransom, but in the climax of the novel, he attempts to explain them to Oyarsa in Malacandran, a language of which he possesses only a beginner's grasp. The result is a comedic irony where the pompous and arrogant Weston appears to be like an ignorant, tantrum-throwing toddler in the presence of the great Oyarsa.
The Irony of the Sorns
The Sorns are giants: inhumanly tall and remarkably thin, covered with feathers and with seven long fingers on each hand. Weston and Devine think of them as dangerous savages, and bring Ransom as a human sacrifice. The sorns, however, are nothing of the sort; in fact, they are highly erudite intellectuals who delight in nothing as much as sitting around in contemplation of abstract scholarly ideas.
The Irony of the Hrossa
The hrossa also have a deceptive appearance: they look like giant otters, but they are intelligent, communicative beings with an intense appreciation for art of all forms, especially poetry. They prove to be even more "human" than Weston and Devine, who murder three of their kind with animalistic brutality and mindlessness.
The Irony of Science
The race of men has progressed in the area of science to the extent that they are capable of traveling between worlds. Ironically, as Oyarsa points out, in all other respects they are as primitive and base as unguided savages, far behind the moral and artistic quality of other planets.
The Irony of the Sleeping Hross
In the climactic scene where Weston converses with Oyarsa, there is an old hross who has fallen asleep. Weston thinks this creature is a ventriloquist speaking with the voice of "Oyarsa," so he directs his invective against this poor, old, sleeping creature. Weston eventually realizes his ironic mistake when the hross wakes up, realizes his error of slumber, and waddles out of sight.