I think we may have to start by a definition that we can all agree on
Reason is the capacity for consciously making sense of things, applying logic, establishing and verifying facts, and changing or justifying practices, institutions, and beliefs based on new or existing information
It has never occurred to me that it would be necessary to defend it until I met IB and Malcolm G. He writes in a comment on IB’s post, I will quote him entirely, that
IB, it’s so interesting that we often agree with each other even though I’m an atheist and an anarchist to boot. There are so many important areas of our life where reason is unable to help us. Reason for example, and I think you will agree with this, cannot help us choose between fundamental values just as reason cannot help us decide which is the best play writer, Shakespeare or Sophocles. We simply have no way to objectively compare a life lived according to the Sermon on the Mount to a life lived according to the Bushido code of the Samurai.
Furthermore, we live in a society run by moral rules and traditions which have evolved over time, with those groups surviving which had the most successful rules and traditions. For example, some groups accidentally developed a favorable tradition which we now call private property. These groups were very successful but the groups themselves have long since forgotten why they were successful, if they ever knew it in the first place. So we owe much of what we have achieved to a moral tradition which was never rationally designed nor indeed, intentionally created. Maybe faith in moral traditions is nature’s way of putting obstacles in the way of naive rationalists bent on replacing successful rules they have not designed with unsuccessful rules which they have?
In the first instance, the only thing, if anything differentiates us from the brutes is reason. Anyone who thinks that we can dispense with reason should go live with the brutes.
If reason can’t help us in choosing between fundamental values, whatever these are, what can?
I know he and many others will be quick to respond reason cannot help us on matter of taste. If reason is a way of making sense of things, then it is a guide in matters of taste.
And why would reason not help us arbitrate on who is the best playwright? where we expect each one to give a reason for their preference?
Isn’t all experience subjective? So that the only way we can compare lives is subjectively?
Why do we follow the tradition? Is it not because it comports with our reason? We have stopped, generally, from burning people at the stake for heresy because we have reasoned it was a stupid thing to do? Haven’t we generally stopped burning witches because we have reasoned it was really backward and inhuman and that there never were any witches to begin with?
I find people who disparage reason while also claiming maintaining they are reasonable and rational strange and bordering on the insane. I can excuse IB. Her username is insanity- that is, in her case the ship has sailed and their no help. For others, not so fast.