Logical possibility should be distinguished from other sorts of subjunctive possibilities. But the relationship between modalities (if there is any) is the subject of debate and may depend on how one views logic, as well as the relationship between logic and metaphysics . For example, many philosophers following Saul Kripke have held that discovered identities such as "Hesperus = Phosphorus" are metaphysically necessary because they pick out the same object in all possible worlds where the terms have a referent. However, it is nonetheless logically possible for “Hesperus = Phosphorus” to be false, since denying it doesn't violate a logical rule such as consistency. Other philosophers are of the view that logical possibility is broader than metaphysical possibility, so that anything which is metaphysically possible is also logically possible.