According to Hobbes, individuals care about their relative standing in a way that shapes their social interactions. To model this aspect of Hobbesian psychology, this paper supposes that agents have social preferences, that is, preferences about their comparative resource holdings. Introducing uncertainty regarding the social preferences of others unleashes a process of trust-unravelling, ultimately leading to Hobbes’s ‘state of war’. This Trust-unravelling Model incorporates important features of Hobbes’s argument that past models ignore.

Suppose we assume that the parties in the original position took Kahneman and Tversky's prospect theory as constituting their general knowledge of human psychology that survives through the veil of ignorance. How would this change the choice situation of the original position? In this paper, I present what I call ‘prospect utilitarianism’. Prospect utilitarianism combines the utilitarian social welfare function with individual utility functions characterized by Kahneman and Tversky's prospect theory. I will argue that, once prospect utilitarianism is on the (...) table, Rawls's original arguments in support of justice as fairness as well as his arguments against utilitarianism are, at best, inconclusive. This shows that how implausible a choice for utilitarianism in the original position is heavily depends on what one assumes to be general knowledge of human psychology that the original contracting parties know. (shrink)

This paper considers contractarianism as a method of justification. The analysis accepts the key tenets of contractarianism: expected utility maximization, unanimity as the criteria of acceptance, and social-scientific uncertainty of modelled agents. In addition to these three features, however, the analysis introduces a fourth feature: a criteria of rational belief formation, viz. Bayesian belief updating. Using a formal model, this paper identifies a decisive objection to contractarian justification. Insofar as contractarian projects approximate the Agreement Model, therefore, they fail to justify (...) their conclusions. Insofar as they fail to approximate the Agreement Model, they must explain which modelling assumption they reject. (shrink)

John Rawls famously argued that the Difference Principle would be chosen by any rational agent in the original position. Derek Parfit and Philippe Van Parijs have claimed, contra Rawls, that it is not the Difference Principle which is implied by Rawls’ original position argument, but rather the more refined Lexical Difference Principle. In this paper, we study both principles in the context of social choice under ignorance. First, we present a general format for evaluating original position arguments in this context. (...) We argue that in this format, the Difference Principle can be specified in three conceptually distinct ways. We show that these three specifications give the same choice recommendations, and can be grounded in an original position argument in combination with the well-known maximin rule. Analogously, we argue that one can give at least four plausible specifications of the Lexical Difference Principle, which however turn out to give different recommendations in concrete choice scenarios. We prove that only one of these four specifications can be grounded in an original position argument. Moreover, this one specification seems the least appealing from the viewpoint of distributive justice. This insight points towards a general weakness of original position arguments. (shrink)