 The A Prioricity Condition: The provisional equation must be a priori true: there must be a priori covariance of best opinions and truth. (Justification: ‘the truth, if it is true, that the extensions of [a class of concept] are constrained by idealised human response—best opinion—ought to be available purely by analytic reflection on those concepts, and hence available as knowledge a priori’ (Wright 1992: 117)). This is because the thesis of judgement-dependence is the claim that, for the region of discourse concerned, best opinion is the conceptual ground of truth).