 As the above survey suggests, there are plausible objections to each of the dominant justifications for the duty to obey the law. (For helpful assessments of other theories, see also Wasserstrom 1963; Smith 1973; Simmons 1979; Huemer 2013.) Each leaves significant gaps in the authority of law. This is not an impossibility proof—only anarchists like Wolff think that justified political authority is impossible. But neither is it just the familiar problem that philosophical theories provide only a rough fit to our casuistic judgements. The problem is that the typical justifications for authority are all sensitive to context in a way that the claims of law are not. To put it another way, law itself purports to determine how far and in what contexts its authority binds. (For a formulation of the sceptical view that explores its relationship with legal positivism, see Kramer 1999.)