Kant (posting...): The only thing that is truly good, in and beyond the world, is the good will.
Commenter 1: Where's your empirical evidence?
Kant: I don't have any. In fact, I can't prove this with empirical evidence. That's actually the point.
Commenter 2: That's nonsense. Why should we ever believe it if you can't give us an example?
Kant: Well, try this--think about the concept of doing your duty. When you really think about duty, it is contained in the concept of a good will, a will that is determined only by the fact of duty, not by any circumstances, intentions, or impulses.
Commenter 1: Well, now you are just talking in circles. Why won't you give us a reasoned argument? I don't want to waste my time on this if you can't prove to me that's it worth it.
Commenter 2: And, by the way, no such thing exists, so this is stupid.
Kant: As I said, this can't be proven empirically. It's a statement about the universal principle of morality or the form of the moral law, which, incidentally, is the same thing.
Commenter 1: Like I said, you're talking in circles.
Commenter 2: Now you're simply incoherent. Which is it?
Kant: The idea is that of a categorical imperative, an imperative binding in and of itself. Such an imperative would be knowable by reason alone and as such, it would apply universally, to all rational beings as such. So, we could test our moral judgments and ask whether they could apply universally or whether we could will that they would apply universally. In fact, we can state this in different ways, as a universal law or in terms of a self-legislating kingdom of ends.
Commenter 1: This is just hair-splitting. I never wanted to know anything about morality anyway.
Commenter 2: Yeah, me either.