 The Darwiche-Pearl postulates express an intuition about the epistemic ordering of possible worlds, namely that when we revise by a sentence \(p\), then the ordering among \(p\)-worlds should be unchanged, and so should the ordering among \(\neg p\)-worlds. The change takes the form of a shift of the relative positions of these two parts of the original ordering of worlds. A large number of proposals for such shifts have been put forward, but opinions differ widely on the adequacy of these proposals.