Swift's style is influenced by the 18th-century essayists he satirizes, drawing on a long tradition of persuasive essay writing made popular by earlier writers like Milton. Swift mixes classic elements of persuasive essay style—including the use of pathos, logos, and ethos—with his characteristic sarcasm and deadpan writing style to produce effective satire.
Swift's deadpan method of writing, in particular, serves as the fundamental aspect of his criticism. He tends to present absurd, shocking ideas in academic-sounding sentences, as exemplified below:
I have been assured by a very knowing American of my acquaintance in London, that a young healthy child well nursed is at a year old a most delicious, nourishing, and wholesome food.
Note that the first half of this sentence, up until the word "delicious," is entirely ordinary. It would not be out of place in another essay discussing children's health. This academic diction contrasts with the extreme suggestion included in the latter half of the sentence. Swift makes no attempt to justify the absurdity of this statement, moving on to provide more detail in the next sentence, as though child cannibalism were an entirely expected suggestion.
This deadpan style of writing ultimately services Swift's satire by reinforcing the narrator's sincerity. The Proposer must—as the vehicle for Swift's satire and criticism of his surrounding society—lack self-awareness, or else he would simply become an ineffective stand-in for Swift himself.