John Keynes' essay, Economic Possibilities for our Grandchildren, was written in 1930, and is only about 3000 words long. The third last paragraph is the best summary of the way ahead for mechanized society I have seen. Science fiction writers were thinking along similar lines, notably H G Wells, but John Keynes expressed the formula for a sensible mechanized society so well that I regard the publication date of 1930 as a turning point in the twentieth century. The link is below.
http://www.econ.yale.edu/smith/econ116a/keynes1.pdf[Mod Edit: Link fixed.]
