To be truly rational we need to acknowledge the limits of our rationality: nothing is more irrational than an unwarranted faith in reason. - Julian Baggini

In this way we can see that political reason is as much – if not more – bottom-up than top-down. Rationality requires attending to objective reasons for belief and many of the most important such reasons are provided by what we observe in the world. Indeed, what we observe is of primary importance: there is no hope of understanding justice, for example, if we attempt to do so purely by examining the concept without any reference at all to what we perceive to be just or unjust in the world.

Think of any serious participant in intellectual life. Is there any who does not try to be as comprehensible as is possible? Many are so incomprehensible that we doubt them, but this is almost always a failure of execution, not a success born of intent. Does anyone assert that it is not possible for anyone else to assess the merits of their claims? Very few, and the whole raison d’être of publishing and discussion is precisely that others are, in principle, capable of assessing what they have read or heard and sharing these assessments. Does anyone declare that what they have to say is wholly relative to the interests only of a particular sector of society? Surely not. Even as we acknowledge our biases and partial perspectives, we strive to overcome them as much as is possible. Does anyone think there is no way they could possibly be wrong about what they believe? We may sometimes feel this, but the fact that we nonetheless leave ourselves open to criticism and take those criticisms seriously shows we are committed to the idea that rational inquiry demands we treat our beliefs as defeasible. And finally, when you have seen someone provide what seem to you good reasons for their accepting their position, is your agreement not in some sense involuntary? Similarly, can you not help but dismiss arguments that seem to you weak or ill-founded?

There is an irony here. On the one hand, all of these mistakes point to hubris, a belief that human reason is more powerful than it really is. But on the other, all these mistakes implicitly acknowledge how limited the power of reason is, because they require us to simplify our conception of the world in order to make it tractable to reason. It is as though in order to preserve the illusion that human reason is mighty, we have to rig its challenges to make them easier to overcome.