G. A. Cohen argues that Rawls’s difference principle is incompatible with his endorsement of incentives inequality—higher pay for certain professions is just when that pay benefits everyone. Cohen concludes that Rawls must reject both incentives inequality and ‘institutionalism’—the view that egalitarian principles, including the difference principle, apply exclusively to social institutions. I argue that the premises of Cohen’s ‘internal criticism’ of Rawls require rejecting two important parts of his theory: a ‘subjective circumstance of justice’ and a ‘shared conception of justice’. (...) These are important parts of Rawls’s ‘constructivism’. Constructivism is the view that a conception of justice is the solution to a practical interaction problem and is solved in part by examining the facts of the problem. Thus, an upshot of my arguments is that this Cohen/Rawls dispute reduces to another dispute over ‘constructivism’. (shrink)