Pat, thanks for splitting this off into a separate thread. It’s a great question and deserves focused attention.
I want to start by pushing back on the way you’ve framed the question. I think the trouble starts with the word “realm.” I don’t actually think there are two “realms” — a normative one and an empirical one — sitting side by side like adjacent countries on a map. That way of framing it invites exactly the puzzle you’re raising: what kind of discovery tells us there are two realms? Is that discovery itself in one realm or the other? And then we’re off to the races.
What I’d say instead is that the distinction is between two irreducibly different dimensions of a single activity — the activity of knowing. When I make a judgment, that judgment has a causal history (neural processes, developmental factors, social context, etc.) and it has a normative status (it’s warranted or it isn’t, the evidence is sufficient or it isn’t). These aren’t two separate things I’m doing; they’re two aspects of the same concrete act. But — and this is the key point — neither aspect is reducible to the other. The causal story doesn’t deliver the verdict on warrantedness, and the normative assessment doesn’t tell you which neurons fired.
So to answer your question directly: the claim that there’s an irreducible normative dimension to knowing is not an empirical finding in the way that, say, the conjunction fallacy is. But it’s also not a free-floating “ought.” It’s something you discover reflexively, by attending to what you’re actually doing when you inquire. You notice that inquiry has a structure — you raise questions, you grasp possible answers, you marshal evidence, you weigh whether the conditions for affirming are met — and that structure has normative features built into it. Not imposed from outside, but intrinsic to the activity itself. You can’t even formulate the question “is this judgment warranted?” without already operating within that normative dimension.
Hume is relevant here but I think the lesson cuts differently than he intended. He showed that you can’t derive ‘ought’ from ‘is’, and thats right. But the deeper point isn’t that normativity is therefore arational or outside inquiry — it’s that the kind of inquiry that discovers normativity is self-attentive inquiry. You don’t find it by looking outward at relations between physical entities; you find it by attending to what you yourself are doing when you look outward at relations between physical entities. It’s not that reason isn’t part of nature. It’s that understanding reason requires a reflexive turn that empirical method, by design, doesn’t make because its methodological abstractions bracket exactly that dimension.