This is my bastardization of Immanuel Kant "Prolegomena To any Future Metaphysics."
The problem with Metaphysiccal concepts is that their not vary useful. That said, what can we say about the world of things that might be usefull. Language places things in categories, but some things can change category depend on it's environment. All things are things the only question is what category a thing is going into. I should point out their is one category that is empty and It's the none thing category, and the biggest category is the imaginary thing category.
Because I look at things in this Way I found the paragraph of Dan vary vary funny
> Like I say, I don't think the Green exists, and neither does the John
> Clark you describe. I think you exist, but you seem to have a habit of
> defining yourself in terms of things that don't exist.
Onto the ethics of killing identicals. Based on the Golden Rule.
For John it would be ethical to kill identical without knowing their state of mind at the time of their death. And for Dan it would be unethical because Dan thinks state of mind is important. Ethics tells you what you can't do not what somone else can't do :-).
by the by Kant secularized the Gold Rule. (Do unto other as you would have them do unto you.) The Gold Rule is extremely powerful. The basic tenant of ethics in general is if it passes the Gold Rule it cold be ethical. If it doesn't it is defiantly not. The only problem with it is that it is logically flawed. It makes the assumption that we all care about how we are treated...
I hope this seem perteninte to somone