Contractarianism and propertarianism declined in prominence in the nineteenth and early twentieth centuries as utilitarianism became the dominant political theory, but assertions of the Hobbesian hypothesis did not go away. Skeptical empirical writers appeared now and then, especially toward the end of the nineteenth century. But neither the skeptics nor the new evidence had much apparent effect on philosophers asserting the Hobbesian hypothesis.
Utilitarianism (and the broader concept, consequentialism) has many different forms but at the risk of oversimplification, we summarize it as the belief that the morality of an act or a rule depends entirely on whether it increases or decreases overall welfare, by measuring the sum total of all of its positive and negative effects on wellbeing (Kymlicka 2002: 10; Sinnott-Armstrong 2015). To summarize even further, the goal of utilitarianism is to maximize average wellbeing. Utilitarianism, propertarianism, and contractarianism are not necessarily mutually exclusive, but utilitarianism can stand alone. If so, a justified state maximizes average wellbeing, instituting whatever property rights system accomplishes that goal and altering it as necessary to improve average welfare.
Two features free utilitarianism from a need for a Hobbesian hypothesis. First, it has no natural starting point. The monistic goal of maximizing average wellbeing gives no special prominence to stateless societies. All social arrangements, including statelessness, have to be justified against all other conceivable social arrangements by beating them at the goal of maximizing average utility.
Second, utilitarianism has no proviso. It endorses unrestricted average utility maximization without concern for any minimum standard for particularly disadvantaged people (Kymlicka 2002: 10–52; Sinnott-Armstrong 2015). Unlike contractarianism and most versions of propertarianism—both of which theoretically prohibit harming anyone—utilitarianism has no prohibition against harming some to further the goal of maximizing the average. Related theories, such as sufficientarianism and prioritarianism, do have special concern for the disadvantaged, but we do not think it is accurate to consider them as forms of utilitarianism (Widerquist 2010a).
Critics correctly recognize that utilitarianism has an enormous informational problem (Kymlicka 2002: 46). Even assuming wellbeing can be measured and compared interpersonally, how could one gather the evidence necessary to ensure the average person in arrangement X is better off than the average person in all other conceivable arrangements?