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 … - Julian Baggini

Even if we are pessimistic about the chances of changing our political culture to make it more reasoned, we have little choice but to try. In politics, the waters beneath the thin ice of reason are especially rough and icy. The predators that swim in them are opportunistic populists and divisive nationalists, destined to devour the few naïve idealists who are equally blind to the complexities of real politics. Reason might seem to be a meagre defence against such dangers, but it is the only one we’ve got.

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?

I think intellectual honesty demands that philosophers accept this all-pervading normativity more openly. Apart from anything else, this helps explain why philosophy matters. We are not just disputing what is true or false, we are arguing about what we ought to think. Persuasion is not the same as rational argument but every rational argument is and ought to be an exercise in persuasion. Ideas only matter because we ought to believe the right ones. Reason in philosophy is therefore in a sense never disinterested.