"Maximi plane cordis est, per omnia ad dialecticum confugere, quia confugere ad eam ad rationem est confugere, quo qui non confugit, cum secundum rationem sit factus ad imaginem Dei, suum honorem reliquit, nec potest renovari de die in diem ad imaginem Dei."
Berengar, De Sacra Caena. Cited in Charles Peirce, Collected Papers, 1.30. From "The Spirit of Scholasticism," in the first of his 1869 Harvard lectures. Peirce also cites this passage in his essay entitled "Questions Concerning Certain Faculties Claimed For Man."
For Peirce, the genius of Berengar (or Berengarius) lay in pointing out that authority itself must rest on reason, a view that must have seemed "opinionated, impious, and absurd" in his day. (Peirce, Collected Papers, 5.215)(My quick translation: "Clearly it is [a characteristic] of the greatest kind of heart always to seek refuge in dialectic, for to seek refuge in dialectic is to seek refuge in reason; so whoever does not seek that refuge - having been made in the image of God according to reason - abandons his honor, and cannot be renewed from day to day in God's image.")
The standard view of logic was that all premises in logic were either derived from other syllogisms, or from authority. Since syllogisms are made up of premises, it must follow that if we trace our arguments back far enough, all our beliefs must ultimately rest on some authority. This would seem to prove that those who maintain the religious authority are best suited to resolve disputes.
Berengar argued, in his disputation with Lanfranc, that it is through the use of our reason that we imitate God and, in that imitation, are maintained and made new in that image. In simpler terms, if you believe you were made by God, then use the mind God gave you. Dialectic - reason in conversation with itself or with others - is a divinely-given place of refuge from error and confusion. This doesn't mean reason can't go awry; it's just a reminder that giving up on reasoning is not as pious as it might seem at first.