Medieval Effects of Sin
During the Middle Ages, insufficient attention was given, in general, to the problem of sin as it relates to our reasoning process.... Because the effects of sin were thought to be less extensive in their application to us (as compared with Reformation thought), in that sin was not seen as radically affecting our reasoning, there was an improper view of the faculty of reason, especially with respect to reason’s ability to understand and discern God’s revelation and his existence.