The self-evident existence of reason, logic, and intelligibility are strong evidence for God. Reason is a human faculty that defines humanness and points to a rational universe. This in turn points to the principle of reason, or the "Logos" developed by Heraclitus and other Greek philosophers, and later by the Apostle John (1:1). Reason and its corollaries emerge like aspects of language and complement each other, like speaking and listening. Indeed, mutual communication works because of reciprocity, which is a root form of intelligibility.

This structure or order is best explained by a rational, divine Mind. This, then, is an exploration of the role of the Logos principle in the human experience and condition that we often refer to as Reality. It is an attempt to answer these four questions: Why do reason and logic work? Why do we believe and trust in them? Why do we expect things to make sense? Why does anything make sense at all?

The first part of this book will touch on the relationship between reason and faith, but it is primarily concerned with reason, and logic its foundation. Faith is not the suspension of reason, nor must it be 'blind' to qualify. They are rational complements. Even simple faith has reasons attached to it and involves the use of reason. Faith, in part, is the application of reason to metaphysical questions and propositions. Theists must apply reason when thinking about God (even if He might not actually exist).

In modest terms, He probably does exist, and there are ample reasons for near-certainty, especially the existence of reason and logic themselves. Add to these intelligibility, order, reciprocity, and another concept that becomes very prominent toward the end of the book, complementarity. The main argument of this book is: Because reason exists, God exists. It's not that through our powers of reason we can be certain of the existence of God, but rather that the existence of reason and its corollaries point compellingly to God.