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… - Julian Baggini

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.

This point is, in essence, the most important and overlooked one regarding the rationality of ethics. The traditional dispute between Kantians and sentimentalists rests on an assumption that to be rational, morality must be grounded on a priori principles of disinterested reason. This is false. If we understand what rationality means in an appropriately catholic way, we see that it it is a matter of providing reasons for belief and that the sources of these reasons are not confined to a priori principles of logical or scientific facts. Once we accept that, we can see that although the Kantian project of founding ethics on pure reason is doomed, reason is still at the very heart of morality.

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?