I've been following a troll by the name of Young Apologist who showed up at Skeptico, recently. Mostly, I've been quiet while the others dissect his nonsense line-by-line. He ended up repeating one tired old thing about how you can't use material description to talk about "immaterial" objects like souls and such. And that gets to the title of this post.
Like so many other dualists, he's essentially trying to describe something, not by what properties it has or what it does, but by what it's not. Of course, that leaves him with an infinite amount of room to move goalposts.
In science, you have to define what you're talking about in a meaningful manner. You do this so that you have testable predictions: What will you see when you examine the subject? What will happen when you do X to the subject? If those predictions are wrong, then you can admit you're wrong. Faith works the opposite way: "I am infallible" is the underlying basis of faith. Laying out definitions for the things they have faith in can only create opportunities for them to be demonstrated as wrong.
That's why they use nonsense words like "supernatural" to avoid defining their terms. Of course, this has a nasty habit of removing evidence from the process. If there's no evidence, no predictions, or anything like that, how do they know? The typical response I get boils down to reassertion of their superiority: They can know the unknowable because they said so.
It's really pathetic.