 Arguments of the second, a posteriori form are more modest in their aims but no less devastating in their conclusions. In this case the aim is not to show that a satisfactory defense of political obligation is impossible but that no defense has proven satisfactory, despite the efforts of some of the best minds in the history of philosophy. All such attempts have failed, according to those who take this line, so we must conclude that only those relatively few people who have explicitly committed themselves to obey the law, perhaps by swearing allegiance as part of an oath of citizenship, have anything like a general obligation to obey the laws under which they live (e.g., Smith 1973; Raz 1979, chap. 12; Simmons 1979, 2001, chap. 6, and 2005; Green 1988, pp. 220–47, and 1996).