This article explores two questions. First, in adjudicating claims under the Human Rights Act 1998 (HRA), should the court defer to the executive or legislature on the ground that the latter two institutions possess superior expertise or information-gathering powers, when such expertise or powers fail to generate persuasive first-order reasons for the court? This article argues that rationality requires courts to defer on these second-order grounds of institutional capacity in situations of judicial uncertainty. Secondly, this article examines an underexplored question in the current literature: when is it justified for courts to consider the government as possessing second-order grounds of institutional capacity that warrant deference? It is argued that rational, impartial and open adjudication in the post-HRA era requires the government to prove its claims of superior institutional capacity, and courts to openly scrutinise such claims by considering a number of factors, including, crucially, the government institution's track record of expertise and credibility.