Reasonable Rejection in Contractualism

Scanlon's states Contractualism as follows ... an act is wrong if and only if any principle that permitted it would be one that could reasonably be rejected [...] (or, equivalently, if and only if it would be disallowed by any principle that such people could not reasonably reject). (Scanlon 1998: 4) I start by making some clarifications to the view, and then raise some difficulties for Contractualism arising primarily from candidate answers to the question of what it takes to reject a principle and how this constrains the notion of reasonableness operative in Contractualism. I suggest two idealized conceptions of what it is to reject a principle, and find that Contractualism fares poorly on either.