A leading scientist speculates on far-future scientific developments and their possible impact on the human condition. Dyson (From Eros to Gaia, 1992, etc.) points out that our culture has apparently lost its long-range vision. Drawing on a fascinating cross-section of scientific and technological history, the professor emeritus at Princeton's Institute for Advanced Study lays the groundwork for a longer view, with a special interest in making the case for what has been called ``small science.'' He argues that massive projects with politically imposed deadlines (e.g., nuclear power plants) are incapable of developing naturally, because any failure is likely to be so massive that it brings all progress to a stop. When a smaller project fails, others can learn from it and build something better. Dyson contrasts two scientific styles: the Napoleonic, with huge teams and enormous budgets, under dictatorial supervision, and the Tolstoyan, in which creative anarchy is the rule. The Tolstoyan can thrive in times when tight budgets force such Napoleonic projects as the Superconducting Supercollidor onto the scrap heap. Looking ahead, Dyson suspects that the greatest surprises will come from the biological sciences. Genetic engineering is barely in its infancy; the visions of Jurassic Park or Brave New World could well become realities within a few centuries. Dyson bravely peers into even more distant vistas, to eras normally the province of science fiction; a million years in the future, the human race is likely to be altered almost beyond recognition--especially if a significant fraction of the population moves off Earth into environments that we can barely imagine. Finally, Dyson examines the interaction between scientific progress and social justice, and asks to what extent science should inquire into the application of its discoveries. At every turn, he illustrates his subject with reference to a wide range of writers and philosophers, making the book a delight to read. Essential reading for anyone who looks beyond the coming millennium.