Definition of “Reason” taken from Faith Beyond Reason by C. Stephen Evans pages 22-23

As I see it, the term ‘reason’ is used in two fundamentally different ways. The concept of reason is partly a normative concept; it represents an ideal; the ideal of a set of processes that are aimed at truth and that give us the best shot of gaining truth. As a normative ideal the concept of reason can potentially serve to criticize any actual, concrete human thinking. We must be open to the possibility that our current ways of thinking and inquiring are not in fact truth-conducive.

However, the concept of reason must have some descriptive content as well; it cannot be purely normative without becoming purely abstract and irrelevant to our actual thinking. We do identify some of our ways of thinking a exemplifying those normative ideals and we hold those ways of thinking up as a measure of thought and inquiry.

Now it seems to me that the idea of rejecting reason in the purely normative sense makes no sense, unless one does not care about truth. By definition, reason in the normative sense represents whatever patterns or methods of thinking give us our best shot at truth; to reject reason in this sense is simply to indicate a lack of concern for truth.

However, it is by no means absurd to question whether particular patterns of thinking that are currently accepted as exemplifying this normative ideal in fact do so. For example, suppose someone identifies as ‘rational’ only those beliefs that can be verified by scientific evidence. To question the competence of ‘reason’ in this narrow sense is not to reject reason as an ideal; it can be convincingly argued that this restrictive view of reason is itself unreasonable, since obtaining scientific evidence itself seems to presuppose some beliefs that cannot be based on scientific evidence.

We must be open to the possibility that the patterns of thinking that are accepted as exemplifying the ideal of reason can be questioned. I shall try to show in succeeding chapters that this is a plausible way of understanding some of the claims of theologians about the limitations of reason.