A Modest Proposal is a hallmark work in the history of satire. Jonathan Swift takes all of the rhetorical tropes, tricks, and flourishes of his time, and spins them into an essay that persuades its readers perfectly to do the exact opposite of what it is suggesting.
The essay was written with a specific audience in mind: the Protestant British aristocracy, who were (naturally) at odds with the significantly poorer Catholic Irish. It opens with a somber paragraph about the poor, in which Swift creates a backdrop of logos (although already not in the best of faith) and supplements it with pathos. He begins by making presumably obvious (to contemporary audiences) claims about the poor’s situation - they live helplessly and desperately, and cannot provide for the amount of children that they bear. Subtle anti-Catholic sentiment is woven into the text in order to encourage an undercurrent of resentment in its Protestant readers: the stereotype that Catholics “breed too much” is employed in full force, and fears about their loyalty to a power other than the British are used in conjunction with it to spin a narrative that the poor are not only draining British physical resources but actively contributing en masse to the detriment of society.
“...for their helpless infants who, as they grow up, either turn thieves for want of work, or leave their dear native country, to fight for the Pretender in Spain, or sell themselves to the Barbadoes.”
He then cites some statistics, makes a show of eliminating sources of error, and comes up with a very large estimate of the number of impoverished children for whom society has no means to provide (again, logos).
The very articulate and matter-of-fact way in which information is presented in this essay is Swift’s method of utilizing ethos. The first portion of the text is structured like a typical joke: some details are given and framed in a way that hints at a normal conclusion (the setup), only to be concluded in a way that subverts the reader’s expectations while still technically conforming to the context (the punchline). In order for a punchline to have the effect intended by its author, its setup must truly suggest to the reader a familiar/credible thought process that prevents them from anticipating “impossible” or “unthinkable” outcomes. Swift adheres to this formula by initially building up a sense of trust in his audience. He presents himself as a credible person by playing up his sensibility - addressing issues without florid language, validating his audience’s ideas and fears, and appealing to “common sense” (“which would move tears and pity in the most savage and inhuman breast.”). At this point, a contemporary reader would have likely seen Swift as a reasonable, well-mannered British gentleman who merely wants a decisive approach to the situation. A new policy, perhaps, or some sort of great social incentive to convert, work, and bear children.
It is thus only more shocking when the reasonable, well-mannered British gentleman suggests an idea so repulsive as to be unthinkable: cannibalizing children.
“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, whether stewed, roasted, baked, or boiled; and I make no doubt that it will equally serve in a fricasee, or a ragoust.”
The whiplash from this single sentence is intentionally worsened by the consistency of Swift’s tone throughout the whole essay. He goes on to propose an extremely detailed plan for the processing of children as livestock, with the exact same rhetorical tools that he used at the beginning to get his readers invested: statistics, the prospect of financial recovery, and anti-”Papist” sentiment. By now, the (presumably attentive) reader is only continuing with the essay out of horror or morbid fascination. They cannot come up with any solid argument against Swift’s points, because their prejudices dictate that they should agree with any proposal that so efficiently does away with the Irish Catholic “problem.” If they are to be honest with their feelings, they must accept that their previous dehumanization of the poor was wrong - otherwise, what would be so repellent about eating the Papists’ children?
This is the brilliance of it: A Modest Proposal applies beautiful rhetoric to something whose repulsiveness it makes no attempt to sugarcoat. The cannibalistic consumption of children is not hidden behind euphemisms; instead, it is discussed so matter-of-factly and objectively that audiences end up horrified by its justification. The essay is meant to - metaphorically - get up in its reader’s face, and ask “What’s wrong? Isn’t this what you wanted?” The reader has two options: to say “no” and betray popular prejudices, or to say “yes” and feel damned.
While rhetoric is ordinarily used to frame or disguise the bare truth of an argument, its ironic usage in A Modest Proposal instead makes the work’s true message painfully clear: poor people aren’t supposed to be treated like livestock.