  According to Raz, the essential role of authorities in our practical reasoning is to mediate between the putative subjects of the authority and the right reasons which apply to them in the relevant circumstances. An authority is legitimate if and only if it helps its putative subjects to comply better with the right reasons relevant to their actions—i.e., if they are more likely to act in compliance with these reasons by following the authoritative resolution than they would be if they tried to figure out and act on the reasons directly (without the mediating resolution). For example, there may be many reasons that bear on the question of how fast to drive on a particular road—the amount of pedestrian traffic, impending turns in the road, etc.—but drivers may comply better with the balance of those reasons by following the legal speed limit than if they tried to figure out all the trade-offs in the moment. The legitimacy of the legal speed limit would thus be derived from the way in which it aids people in acting in better compliance with the balance of the right reasons.