 This apparent middle ground between consent and truth may seem puzzling in several respects. One puzzle is whether there is, in fact, a coherent and stable way of explicating the notion of reasonable acceptability or justification (Raz 1990, 46; Enoch, 2015). But even if we assume the idea of public reason is coherent, we can plausibly ask why we ought to accept this idea, that is, what is the basis for adopting public reason as the relevant standard to evaluate rules and to govern individual conduct? This section considers five different answers to this question (these answers can, of course, also be combined). It is helpful to begin by considering these different positions regarding the basis of public reason, since how one chooses to answer this question often has direct implications for the scope, constituency, content, site, duties, and structure of public reason (see Billingham and Taylor 2020).