In the 1860s the Russian novelist Leo Tolstoy accused historians of muddled thinking when they wrote of progress. Emphasizing the dazzling array of new technologies—in print, transportation, communication (railroads, steam engines, telegraphs, and the like)—historians seemed to assume that such developments necessarily contributed to improvements in the overall welfare of individuals and nations. But Tolstoy was convinced that “progress on one side is always paid back by retrogression on the other side of human life.” For him the growth of cities and newspapers, gas-lighting, railways, and sewing machines, all were either regressive developments or not worth the cost of destroying forests and people's sense of simplicity and moderation. Whether Tolstoy was right or wrong about the effects of such developments is less important than the questions his criticism prompts. What is progress? How is it to be measured? Tolstoy himself equated it with an overall improvement of well-being, which is perhaps as good a definition as any. Thus, the task at hand is to summarize the changing nature of global well-being over the course of the twentieth century, as well as changing perceptions about it.

A key figure in developing the nineteenth-century view of progress, criticized by Tolstoy, was the eighteenth century Scotch economist Adam Smith. He believed that economic progress depended upon the division of labor, free trade, and people pursuing their own economic self-interest.