[LouieFisk]

“You cannot reason a man out of a position he has not reasoned himself into,” as Jonathan Swift put it.”
—
While a correct observation, there’s a bit of irony in the author believing the quote originated with Swift.
https://quoteinvestigator.com/2015/07/10/reason-out

[Blennos]

there’s a bit of irony in the author believing the quote originated with Swift.

I just read the fairly long article. The conclusion is that the quote (much paraphrased by others) did indeed originate with Swift.