Many commentators have pointed out the presence of a tension, even a contradiction or inconsistency, between two theses advanced by Friedrich Hayek: that the growth of institutions ought to be spontaneous rather than consciously designed, and that the conscious design of a constitution is necessary, so as to secure a desirable social order. Our paper shows via textual analysis that, far from being irreconcilable, these two theses, on the contrary, complement each other.