Although your question references Swift's proposal, let me be picky and reframe the question as the speaker's proposal (or the essayist's proposal, or even the Proposer's proposal). We need to make it clear that the speaker in the essay is not the same person as the author and social critic Jonathan Swift. The distinction helps us understand that the essay is satire, and that Swift doesn't actually think Irish society should solve its problems by eating their own babies!
This speaker does rely on others' authority throughout the piece, which adds to its persuasive power. Let's look at some examples, in order from the beginning to the end of the essay.
1. "As I have been informed by a principal gentleman in the county of Cavan, who protested to me, that he never knew above one or two instances under the age of six, even in a part of the kingdom so renowned for the quickest proficiency in that art."
Here, the speaker defers to a "gentleman" to add authority to the statement that kids under six are...
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