Widespread recognition that economic inequality has been growingfor forty years in most of the developed world, and in fact has tendedto grow across most of the history of modern economies, shows thatthe period 1945-1973, when inequality of wealth and income shrank,was a marked anomaly in historical experience. At the time, however,the anomalous period of equality seemed to vindicate a long history ofoptimism about economic life: that growth would overcome meaningfulscarcity and usher in an egalitarian and humanistic period that couldalmost qualify as post-economic. This has not been the experienceof the last four decades. In this intellectual history of the anomalousperiod, we trace the main lines of that optimism and its undoing