... Hume's distinction between matters of fact and relations of ideas prevents the difficulty Quinn imagines.

... Quinn's imaginary scenario does not resemble anything we would recognize as a desire and does hence not constitute a counterexample.

... Quinn's objection was already conclusively refuted by Hume in his Treatise.

... Quinn's own conception cannot work because reason must be "the slave of the passions."

... Quinn misunderstands their position.