[GavinWheeler]

Originally posted by E. Albright:
Well. This depends. Under certain metaphysical systems, one can have non-existent objects that possess qualities. We could, for example, drag out such hideous entities as Platonic Ideals . But of course at that point we should likely fall into a bitter, sectarian squabble as to precisely what "exists" means...

Of course, under Plato's system there is a neat answer to that in the concept of a platonic existence. Personally, if you differentiate between the concept of something and the thing itself, the signifier and the signified, I don't see where a problem exists.

For example we all know that "a unicorn has a horn on its head", but we are talking about the concept, the mythical entity. The concept exists and has qualities, but the thing itself does not. If we try to talk about a physical unicorn having or lacking a horn, we are in quite different territory and should produce the unicorn in question before the debate is sensible.