The point there is, precisely, that Ford is not a conservative, although he parrots conservative talking points. (Well, he can be considered a conservative in the sense that he wants the world to stay as it was when he was younger.)

I was careful to note world history and world literature and not just European - the narrowing down of both studies does not mean that the broader perspective need be restricted to Europe.

The classics (once one gets past the limited question of straight literary quality) are useful especially as an illustration of people thinking differently: Virgil is different from us, and Homer is yet more different from him than we are. Humans are highly programmable and our best evidence is radically different societies. And, of course, study does not necessarily require approbation of values,and encouraging of critical thought requires definitely not agreeing with what you study. (The assumptions of the Anciens are dead as as doornail; our justifications for the classics are, inevitably, going to be those of the Modernes.)

Ironically, given the prevalence of slave societies (classical Europe, India, China, Islamic Caliphate) one of the times and places relatively free of slavery was the high mediaeval period: slavery had ceased to be economic, and so institutions like English thralldom largely lapsed (they had serfs, and indentured servants, but not much in the way of actual slavery). The scaling up of agriculture on plantations is what brings it back.