Rational Choice Theory (RCT) concerns the formal structure of the choices of individuals and the preference ordering behind their choices. It identifies a set of basic properties that rational individuals are supposed to satisfy. The most basic properties of rational preferences are reflexivity, transitivity, and completeness. If the choices include risk, the independence of irrelevant alternatives is thought to be one additional basic property. Many economists believe that these properties not only help us to explain and predict individuals’ behaviors but also have normative force in their own right.

RCT plays a fundamental role in TJ as Rawls contends that parties in the original position would unanimously choose his principles of justice through rational choice. In fact, he refers to the literature of rational choice throughout TJ. At the beginning of TJ (12), Rawls claims that “the concept of rationality must be interpreted as far as possible in the narrow sense, standard in economic theory, of taking the most effective means to given ends,” and that “one must try to avoid introducing into it any controversial ethical elements.” However, he does add several substantive qualifications. First, the rational parties aim to maximize the expectations of primary goods, regardless of their rational plan of life. Second, the rational parties are mutually disinterested and not moved by envy. Third, in considering their rational life plan, the rational parties accept the Aristotelian principle, according to which people enjoy the exercise of their developed capacities, and this enjoyment increases as the capacity gets more developed. These three qualifications do not appear in standard RCT. Rawls adds substantive qualifications and assumptions to the standard RCT because, according to him, the parties in the original position are supposed to not only be rational in a formal sense, but also in their choice situation to represent citizens who have a capacity for reasonableness and a sense of justice.