Abstract

Public reason liberals claim that legitimate rules must be justifiable to diverse perspectives. This Public Justification Principle threatens that failing to justify rules to reprehensible agents makes them illegitimate. Although public reason liberals have replies to this objection, they cannot avoid the challenge of powerful deceivers. Powerful deceivers trick people who are purportedly owed public justification into considering otherwise good rules unjustified. Avoiding this challenge requires discounting some failures of justification according to what caused people’s beliefs. I offer a conception of public justification that accommodates these externalist considerations while positioning Public Reason Liberalism to provide insight into real cases of deception.