The problem is "arguing" as compared to "investigating".

If there's a disagreement about how human minds implement certain ideas, then it's more productive to do experimental psychology than to discuss it abstractly, for the usual scientific reasons: nailing it down to a prediction makes sure that the idea in question is actually coherent, and also there are a lot of potential pitfalls when humans try to use their own brains to examine their own brains.

Though on the other hand, coming up with good experiments for this stuff is really tricky. As Suryc mentions above, you can't just ask people what they mean by "intentional" or whatever, you'll get garbage results. Just like how if you ask somebody with no linguistics knowledge to explain English grammar to you you'll get nonsense back, even if that person is quite capable at actually writing in English.