 This definition, however, raises an obvious question: what does it mean to be physically possible? Roughly, a proposition \(p\) is a physical possibility iff there is some possible world \(w\) where the same laws of nature hold as in the actual world and \(p\) obtains at \(w\). But if this is true, Lange’s definition of lawhood seems to be circular, since being consistent with the laws (of the actual world) is ultimately part of the definiens of being a law (of the actual world). Lange (2005, 2009a, 25–28) recognizes the problem of circularity and offers an alternative account of laws in terms of the notion of stability. It says, roughly put: 