This article takes seriously the relationship between culture and a constitution. It suggests that three aspects of New Zealand cultural attitudes to the exercise of public power are salient: egalitarianism, authoritarianism, and pragmatism. None of these attitudes support the constitutional norm of the rule of law and separation of powers in New Zealand, making that norm vulnerable. The salient New Zealand cultural attitudes to public power do reinforce the other three key norms of the New Zealand constitution: representative democracy; parliamentary sovereignty; and the unwritten and evolving nature of the constitution. The last of these is the most internationally distinctive aspect of New Zealand’s constitution and resonates with both our British constitutional heritage and the Māori notion of tikanga; our constitution is not a thing but a way of doing things.