Professor Kolakowski, originally of Warsaw University and now teaching at All Soul’s, Oxford, first came to the West’s attention in the 1960s as a philosophical spokesman of “revisionism”—the dissident movement of humanist intellectuals inside the Soviet orbit. In his most recent work, he has abandoned that position as futile and now is no longer writing to reform Marxism but to show its absurdity.

To be sure, Kolakowski’s concerns had always been different from those of the Zagreb school and other products of the crisis in Marxism. His thought had never been shaped by Marxism as taught in the Communist universities; it ...