Convergence and Consensus in Public Reason

by Kevin Vallier


Reasonable individuals often share a rationale for a decision but, in other cases, they make the same decision based on disparate and often incompatible rationales. The social contract tradition has been divided between these two methods of solving the problem of social cooperation: must social cooperation occur in terms of common reasoning, or can individuals with different doctrines simply converge on shared institutions for their own reasons? For Hobbes, it is rational for all persons, regardless of their theological beliefs, to consent to the sovereign's power. But for Locke, only Protestants with a shared theology could be party to the social contract. Rousseau thought that private reasons are not part of the general will, and in Kant's hypothetical contract, pure noumena reach common principles for the social order through the same reasoning process. In A Theory of Justice, John Rawls agreed with Rousseau and Kant: selecting the principles of justice requires modeling parties to the original position as having identical reasons. But in Political Liberalism, Rawls embraced the idea of an overlapping consensus, which accords distinct reasons justificatory force.