Islam's Eclipse of Reason gives a brief overview of the history of Islam's "prophets of reason." (the suppression of the Mutazilites and Al-Ghazali's anti-Hellenistic victory; and notes how Christianity avoided similar temptations in the medieval age.)
.. another piece highlighting, again, that Benedict's main target, so to speak, was the "Enlightenment Project."
... and, can Christians and Muslims actually dialogue? Well, it's difficult, it seems.