This article considers the contentious invocations of history that have become prominent in debates about English public law. It presents them as uses of history not simply to understand English public law but to reform it, through the reconstruction of historic authorities or reappraisal of historical sources. This article addresses the criticism they have attracted by distinguishing different kinds of orthodox and unorthodox reformist history. It advocates their transparent use and thoroughly deliberative history for reformist purposes in public law. It does so in three distinctive ways: first, by suggesting implications of Coke's dictum on causal understanding for whig historical approaches in the common law; secondly, by reassessing Maitland's dichotomy between the lawyer's logic of authority and the historian's logic of evidence; and, thirdly, by arguing that much can be learnt from the methodological caution, deliberation and rigour promoted by comparativists in their developed literature on legal transplants and law reform.
