 John Locke in the second of his Two Treatises of Government (1689) emphasized the importance of governance through “established standing Laws, promulgated and known to the People”. He contrasted this with rule by “extemporary Arbitrary Decrees” (Locke 1689: §§135–7). Now the term “arbitrary” can mean many different things. Sometimes it means “oppressive”. But when Locke distinguished the rule of settled standing laws from arbitrary decrees, it was not the oppressive sense of “arbitrary” that he had in mind. In this context, something is arbitrary because it is extemporary: there is no notice of it; the ruler just figures it out as he goes along. It is the arbitrariness of unpredictability, not knowing what you can rely on, being subject, as Locke put it (1689: §137), to someone’s 