A thought: [foreign: circa] a century ago, say, the thought that gay people deserved equal treatment was probably so absurd that it didn’t even need to be discussed, because no one thought it was true. Then at some point it became a debatable proposition, and now it’s so obviously true that it doesn’t need debate; the generation that believes gay people don’t deserve equal rights will die off soon enough. There are plenty of other obvious examples of this phenomenon. Consider intermarriage between the races, for instance. If you go back far enough, probably religious toleration would fit in the same bucket.
So I wonder what sort of issues are, at this very moment, in the first phase of that evolution: things that even we (who consider ourselves more enlightened than our benighted ancestors) consider so absurd or so obvious that no one even bothers to discuss them, which will eventually become topics of vigorous debate, and will later on become obviously true or obviously false, respectively. I can dream that maybe “the nation-state is a sensible grouping of human beings” or the related “it is right and just that we treat those who live on the other sides of an arbitrary border differently than we treat our own families” will one day become debatable. Or maybe even those are too explicit; maybe the sort of propositions that we take for granted and will one day reject are exactly those propositions that I couldn’t even think to write down.
Phrased this way, it could be seen as a hopeful question — part of our habit of viewing history as a vanguard marching ever forward in the direction of social liberalism. (I think this might be “The Whig Interpretation of History”, after the book of the same name by Herbert Butterfield. Though it sounds slightly different.) I can see this going in a very illiberal direction as well, however. E.g., maybe there was a time when it was considered obvious beyond the point of discussion (or even of conscious thought) that we lived in something called a “society” in which we were more than just disjoint libertarian billiard balls colliding inelastically into one another. Maybe it was once considered obvious beyond the point of discussion that the main way in which an industrial democracy cares for its least fortunate was by way of its government, which was largely expected to spend money wisely. And so forth. You can imagine any of these slowly becoming less true. And when they become less true, you can imagine them becoming less true in an exponentially-increasing way: if all your friends believe that the less-fortunate are largely shirkers living off the dole, that might cause you to feel the same way (or maybe it’s not causal).
So there’s nothing necessarily liberal about this sort of change, if indeed it happens. I’d like to talk to an actual historian about how one might measure this sort of change. I imagine it would be difficult: almost by definition, the ideas which are believed so widely that they’re beyond the reach of conscious thought are those which few people will ever bother to write about. Extracting earlier societies’ unconscious beliefs might involve digging into the unspoken assumptions behind what they *are* saying.