The Frankfurt School popularized historicism—the belief that reflection itself is a part of history, which is to say that earlier thoughts are historically conditioned by the circumstances in which the thinkers lived, and should be seen in that light; and that what passes for “knowledge” is marred by the historical time and place in which that knowledge appeared. (This idea was present already in the second part of The Communist Manifesto.) The insights that a more positivist outlook claims to be certain, based on sensory data, historicism will consider uncertain and necessarily bound by subjective value judgments. A part of this view is the concern—and the French postmodernists will pick up this point—to identify, isolate, and thereby exorcise every sort of domination that any group might have held over any other group.