Philadelphia Inquirer staff-writer Hine, who looked back in his superb Populuxe (1986) at American life of the 50's and 60's, now looks ahead--tentatively--to the future. Predicting is not Hine's game: He does not venture boldly out on limbs, but rather examines thoughtfully how we got where we are and how and why our ideas about the future have changed. His optimism is a limited one, based on a concept he terms ``subtlety.'' The subtle approach, in his view, implies diversity, flexibility, a rejection of single solutions or single standards; it means shaping technology to advance human aims rather than reshaping humans to meet the demands of technology. To demonstrate, he offers as a small example of nonsubtle progress the modern Red Delicious apple--developed by technology to travel well and be eye-appealing, yet offering little to human taste buds. Subtle progress, he says, would bring us no single apple but ones that differ with place, season, and intended use- -apples designed not for their suitability for mass production and marketing but for human consumption. Application of subtlety to larger problems is suggested, but Hine does not attempt to solve the world's problems. He notes that subtlety's chief tools- -the computer, materials engineering, and genetic engineering-- are available; what is needed is the willingness of people to reexamine their values. Hine sees the creation of a future in which we would like to live as a possibility dependent on both technological sophistication and changed attitudes toward consumption, energy use, and the physical environment. Includes sources and suggested readings. Some hard thoughts about the future of life on this planet by one who clearly enjoys the thinking process but is uneasy about where those thoughts lead.