This article examines the process of constitutionalisation that is ongoing in English administrative law. It does so by focusing on two key questions which, although hitherto largely overlooked by commentators, are beginning to receive attention in the courts. The first question - the 'sin' of omission - relates to the question of how the courts should respond when an agency has not consciously approached a decision through a rights-based framework. The second question - the 'sin' of commission - asks how courts should respond when an agency explicitly reaches a decision on the basis of rights and proportionality. The answers we give to these questions will help to define the nature of the emerging 'culture of rights'. Staking out a position against 'hardline' proponents of rights-based judicial review, I suggest, first, that agencies should not be placed under a duty to articulate decisions through a rights-based framework and, second, that some provisional weight should be accorded to an agency's own assessment of the rights issues at stake.