A recent edition of New Scientist (26 July 2008) carried a feature entitled What's Wrong With Reason? in which 7 commentators outlined the limits of reason as a tool for finding truth. There is a trap with this sort of article, that people may use the fact that some learned people point out the limits of reason as an excuse for believing all manner of quite unreasonable things. That being said, the article does ask important questions - questions which seem almost blasphemous to many in our science and reason besotted culture.
The two commentators who most interested me were the great linguist Noam Chomsky, and Chris Frith, a neuroscientist, who point out that neurologically, no-one understands reason anyway. Some interesting experiments (such as this one) show that far from making "reasoned" decisions about even such simple matters as what car we are to buy or what we are to eat for breakfast, the overwhelming bulk of our thinking occurs unconsciously and reason exists as a post hoc justifier: that is, that after the complex and hidden systems of our brains have made their choices, reason is employed afterward to make up a story to tell ourselves about why the decision was made. As the Anglican Church tears itself apart into camps all making "reasoned" cases for their own points of view, this observation should give us pause for thought.
Since the enlightenment, reason has become the overwhelming paradigm of thought in the West; with the rise of the scientific method, reason alone has become the standard by which everything is judged. When I went to theological college in the 1970s even Christian theology had been shoe-horned into the scientific method; text were examined as cultural and historic artifacts and we responded to them objectively, writing essays that were reasonable and tried, as far as possible to conform to the scientific method. The effect of the texts on our faith was never discussed. Such subjective responses to the material were discouraged as an interference in the the critical examination of the material. It's no wonder so many of us foundered in our faith at St. John's College. It's no wonder so few of us learned to preach; instead we learned to write essays which we then read to our congregations with fairly predictable results.
It's not reason per se that is the problem but rather the exaltation of reason as the only touchstone of truth. One of my favourite books is John Ralston Saul's Voltaire's Bastards: the Dictatorship of Reason in the West in which Saul examines how our Western culture has become besotted with reason, and reason devoid of any other corrective considerations has been employed to the point where, in the name of reason, extremely unreasonable things are done. On his title page he says,
Reason is a narrow system
swollen into an ideology
With time and power it has
become a dogma, devoid of
direction and disguised as
Like most religions, reason
presents itself as the solution
to the problems it has created.