I have described the common denominator in Foucault's several studies as a critical concern with the question of the relationship between forms of rationality and forms of power. The identification of such a common theme in Foucault's work invites a comparison with two other types of analysis which have presented criticisms of the effects of particular forms of rationality, namely those to be found in the work of Max Weber and in the work of the critical theorists of the Frankfurt School. Comparison will be restricted to an exploration of what might seem to be parallel themes and conceptual similarities between the work of Foucault and that of Weber and the Frankfurt School respectively.