An implication of the doctrine of public rules, therefore, is that we have reasons to object to highly epistemically demanding principles of justice that fail the tests of determinacy, accessibility, and/or verifiable compliance. As an example of this, let us consider G. A. Cohen’s claim that justice requires citizens to internalize an egalitarian ethos that condemns self-serving behaviour and, subject to a personal prerogative and special labour burdens, requires citizens to be guided by a concern for the least advantaged when making occupational choices (2008: part 1). Rejecting this possibility on the grounds that it violates the doctrine of public rules, Williams writes that