This thesis deals with the relation between reason and unreason in the thought of Max Horkheimer and Theodor W. Adorno. We extrapolate from some central categories in their writings, particularly those of subjective reason, objective reason and enlightenment, in order to elucidate the critical theory of religion that is suggested by their notion of a dialectic of enlightenment. This thesis argues that, for Horkheimer and Adorno, spiritual belief and practice stand in mutually determining relation to so-called enlightened reason. It considers unreason in the form of primitive superstition, established revealed religion, and the present-day, Western "religion industry". Unreason is held to combine elements of subjective and objective reason, and thus both to affirm and to critique domination at various stages of human history. We conclude that the dialectical conception of unreason suggested by Horkheimer and Adorno constitutes an interesting and original critique of the Enlightenment conception of reason and of the traditional Marxist treatment of religion as mere ideology. However, the notion of liberation advocated by Horkheimer and Adorno on the basis of this theory fails to satisfy
