Rational choice and the original position: The (many) models of Rawls and Harsanyi

Abstract

The Fundamental Derivation Thesis asserts that the justification of justice principles arises from their status as rational choices made under specified conditions. Both John Rawls and John Harsanyi utilize the original position as a model of this thesis, yet their approaches diverge significantly in their construction of the rational chooser. Rawls’s model evolved from early strategic frameworks into a middle-period reliance on the maximin rule under a veil of ignorance, eventually shifting toward a “reasonable” heuristic in his later work. Conversely, Harsanyi employs Bayesian decision theory, utilizing the equiprobability assumption and interpersonal utility comparisons to derive average utilitarianism. These models attempt to establish an Archimedean point for social evaluation through a parametric choice by a single individual. However, the move toward increasing abstraction and impersonality creates a tension between the recognitional requirement of impartiality and the identification requirement, wherein actual persons can verify the rationality of the principles. While both theorists successfully model the moral point of view, they struggle to ensure that the resulting principles remain grounded in the deliberative rationality of real agents. The early Rawlsian framework may offer a more viable path for maintaining this connection between abstract justification and individual endorsement. – AI-generated abstract.