In this chapter, I argue that proportionality has represented a fusion of substance and form that is strange to the game-like nature of the common law. It has embodied a method of review, and a way of legal thinking more generally, situated in diametrical opposition to Diceyan analytical positivism. Precisely due to its anti-Diceyan meaning, proportionality has been promoted as a principle that could establish coherence in English public law through the recognition of minimum substantive values. By using proportionality language, English lawyers have sought a little bit of myth and ritual in judicial review. Hence, the spread of proportionality in English public law should be read against the background of the rise of common law constitutionalism. In this respect, the HRA officialised and enhanced more subtle and progressive cultural transformations. The spill-over dynamic of proportionality expresses the continuing search for rationalism and myth in the ongoing construction of English public law.