I dislike the "post utopian" example, and here's why:

Language is pretty much a set of labels. When we call something "white", we are saying it has some property of "whiteness." NOW we can discuss wavelengths and how light works, or whatnot, but 200 years ago, they had no clue. They could still know that snow is white, though. At the same time, even with our knowledge of how colors work, we can still have difficulties knowing exactly where the label "white" ends, and grey or yellow begins.

Say I'm carving up music-space. I can pretty easily classify the differences between Classical and Rap, in ways that are easy to follow. I could say that classical features a lot of instrumentation, and rap features rhythmic language, or something. But if I had lots of people spending all their lives studying music, they're going to end up breaking music space into much smaller pieces. For example, dub step and house.

Now, I can RECOGNIZE dubstep when I hear it, but if you asked me to teach you what it was, I would have difficulties. I couldn't necessarily say "It's the one that goes, like, WOPWOPWOPWOP iiinnnnnggg" if I'm a learned professor, so I'll use jargon like "synthetic rhythm," or something.

But not having a complete explainable System 2 algorithm for "How to Tell if it's Dubstep" doesn't mean that my System 1 can't readily identify it. In fact, it's probably easier to just listen to a bunch of music until your System 1 can identify the various genres, even if your System 2 can't codify it. The example is treating the fact that your professor can't really codify "post utopianism" to mean that it's not "true". (this example has been used in other sequence posts, and I disagreed with it then too)

Have someone write a bunch of short stories. Give them to English Literature professors. If they tend to agree which ones are post utopian, and which ones aren't, then they ARE in fact carving up literature-space in a meaningful way. The fact that they can't quite articulate the distinction doesn't make it any less true than knowing that snow was white before you knew about wavelengths. They're both labels, we just understand one better.

Anyways, I know it's just an example, but without a better example, i can't really understand the question well enough to think of a relevant answer.