Robert Skidelsky is a historian best known for his definitive three-volume biography of John Maynard Keynes; his son Edward Skidelsky is a philosopher. They have collaborated on a book arguing that people in wealthy countries like Britain and the United States work too hard and by doing so miss out on the “good life” — an ethical concept of a life as “worthy of desire, not just one that is widely desired.”

The inspiration for “How Much Is Enough?” is — unsurprisingly, given the father’s preoccupation — an essay by Keynes. It is called “Economic Possibilities for Our Grandchildren” and was published in 1930. Since it is by Keynes, it is ingenious and brilliantly written. It is also dated and unconvincing. It predicted that barring another world war or some comparable tragedy, a century hence per capita income would be four to eight times as much because of continued capital investment. So far, so good; despite another world war, G.D.P. per capita in the United States has increased almost sixfold since 1930 (and about the same in Britain), and we still have 18 years to go before the century is up. Keynes thought the increase in per capita production would lead to a sharp fall in the hours of work; by 2030 a person would have to work only 15 hours a week to maintain his standard of living. The “economic problem” would have been solved, and the challenge would be to fill up people’s leisure time with rewarding leisure activities. This part of Keynes’s paper is wide of the mark. People in wealthy countries like the United States and Britain are working fewer hours per week on average than in 1929, before the Great Depression reduced the amount of available work: roughly 40 rather than 50. But Keynes thought that by 2010 the average would be 20....