William Bartley is a relatively recent figure in the field of philosophy. Rationalism and empiricism are subjects that appear superficially to be neither inviting nor stimulating. They are, however, disciplines which everyone must adhere to if he is to deserve his definition as a rational being. Yet the tu quoque argument about the limits of rationality (with respect to moral choices) has long gone unchallenged. Two leading Protestant theologians of the twentieth century (Tillich and Niebuhr) have embraced as fact the philosophical contention that rationality is logically limited, and that every man makes some ultimately irrational commitment. It is this claim that Bartley sets out to disprove. He argues that the newly developed critical means of reducing error in philosophic thought have greatly extended the area to which rationalism can be applied, and that it is now possible for man to make a choice between competing commitments that is not arbitrary. By making use of rationalism man can arrive at a firmer commitment. Mr. Bartley's thesis is brilliantly argued and the book is highly recommended to every student of philosophy and theology. Unfortunately it is not written so as to be very accessible to laymen.