The relationship between liberalism and democracy is notoriously paradoxical. On the one hand, the justification for democratic procedures most commonly rests on liberal assumptions. Standard liberal arguments for democracy range from the importance of consent due to the moral primacy of the individual, to the role of critical argument and the diversity of opinion for the discovery of truth. On the other hand, liberal institutional arrangements, such as the separation of powers and the rule of law, have frequently been interpreted as constraints upon democracy, albeit necessary ones if democracy is not to undermine itself. The paradox arises from the fact that liberalism provides a philosophical basis for regarding democracy as the only valid source of law whilst apparently appealing to some higher law in order to limit democracy itself. This paradox is embodied in the constitutions of most liberal democratic states. For generally these documents contain provisions – such as a bill of rights guaranteeing the freedoms of speech, assembly and association – designed to secure popular participation in the democratic process, alongside others – such as rights not obviously intrinsic to democratic decision making and mechanisms for judicial review – which seek to limit the power of democratic assemblies.