I say existence is not a property; Everything exists. Darkuncle says that yes, existence is a property; some things exist and somes don't. For example, he says, three-headed humans do not exist. But three-headed humans cannot be an example of anything, because there *aren't* any three-headed humans. Huh? OK, let's try it differently. I'm trying to prove that all animals have one head. Darkuncle says "No, you're wrong, because three-headed humans have more than one head." I say "That argument would be fine, except there are no three-headed humans. If there were, you would be right, but there aren't. Three-headed humans can't refute anything, because there *aren't* any three-headed humans." I may still be wrong (because of two-headed snakes and the like) but Darkuncle's argument is nonsense. I'm trying to prove that everything exists. Darkuncle says "No, you're wrong, because three-headed humans don't exist." I say "That argument would be fine, except there are no three-headed humans. If there were, you would be right, but there aren't. Three-headed humans can't refute anything, because there *aren't* any three-headed humans." I may still be wrong, but Darkuncle's argument is nonsense. Darkuncle needs to find a two-headed snake to refute me. But in this case, *all* possible 'examples' are nonsense---there are no two-headed snakes. Why? Because Darkuncle defined them that way! He's already admitted that none of his examples exist! They're *all* three-headed humans. Darkuncle says that well, we can conceive of things that don't exist. But this is irrelevant. I can make up all sorts of random crap, but that's not an argument. The fact that I can conceive of ninteen-headed baboons, has no bearing whatever on the question of whether or not all animals have one head. I never said that nonexistent things were inconceivable; I just said there weren't any. I can conceive of a counterexample to Fermat's Last Theorem, too, but that doesn't prove the theorem.