Eclipse of reason, Horkheimer's 1947 diagnosis, traces the transformation by which reason lost the capacity to evaluate goals and retained only the capacity to optimize their achievement. Substantive reason asks what ends are worth pursuing—it evaluates the good, the just, the meaningful. Instrumental reason takes ends as given and asks only how to achieve them efficiently. The eclipse is the progressive displacement of the first by the second, until a culture organized around instrumental efficiency loses the institutional and cognitive apparatus for asking substantive questions with the seriousness instrumental questions automatically command. The transformation is not experienced as loss because instrumental reason delivers measurable results: greater productivity, faster execution, more output per input. What cannot be measured—meaning, beauty, moral weight, the quality of human experience—has no metric and therefore no validity in a culture that has made measurement the standard of truth.
Eclipse of Reason
In The You On AI Field Guide
Horkheimer's analysis identifies the Enlightenment's self-betrayal: reason born to liberate humanity from myth becomes an instrument of new domination