Hillier compares Chesterton to Dr Johnson, whom he physically resembled thanks to his dropsical belly and rolling gait, and whom he often impersonated in pageants. But Johnson's gruff dismissals – of Scotland, of opera, of Sterne's Tristram Shandy, and of anything or anyone who irritated him – were the expression of quirky prejudice; unlike Chesterton, he never pretended to papal infallibility. Johnson prevailed by bullying Boswell, but Chesterton threatened anathema, as when he disposed of the Enlightenment by announcing: "I know of no question that Voltaire asked which St Thomas Aquinas did not ask before him – only St Thomas not only asked, but answered the questions." There speaks a man with a closed mind, a neo-medievalist who abhorred Jews and pined for the return of an agrarian feudal economy in which with every man would be allocated "two acres and a cow".
Once someone says that Johnson — a man who by his own admission “talked for victory,” and was labeled "The Great Cham [Khan] of Literature" (by Oliver Goldsmith) for good reason — “never pretended to papal infallibility,” you need to be on your guard when he says anything else. Though Johnson is the incomparably greater writer, he and Chesterton manifested a similarly complex balance of confidence and vulnerability. And only a very closed mind — or a very ill-informed one — could deny that Aquinas did indeed anticipate and respond to the key questions posed against the Deity by Voltaire. One may not agree with the Angelic Doctor’s answers to questions Voltaire and his admirers thought unanswerable, but they are there.
Chesterton in that passage is merely trying to point out that our ancestors did not believe as they did merely out of ignorance. They thought about many of the same issues Whiggishly self-congratulatory late-moderns think about, but often came to different conclusions. And it’s actually rather instructive to discover what those conclusions are, and how they reached them. Aidan Nichols’s Discovering Aquinas is quite helpful in this regard.