Edmund Morris, Random House, 783 pages, $38. Edmund Morris died this past May of a stroke at the age of 78, having written the final sentence of “Edison” several months before. A figure of astonishing brilliance and manic productivity, Thomas Edison cared so little for the feelings of other people that he saw no reason to keep anything bottled up inside. His archive runs to 5 million pages, giving Morris much unfiltered material. For some unexplained reason, Morris decided to write this saga in reverse, beginning with Edison’s final years and working backward to his birth in small-town Ohio in 1847. It’s the biographical equivalent of F. Scott Fitzgerald’s “The Curious Case of Benjamin Button.” At a minimum, it takes some getting used to, because we’re never quite certain how one event builds upon another or whether a character who appears early in the book (but late in Edison’s life) is central to the story. Writing about someone who filed more than 1,000 patents, whose inventions ranged from incandescent electric lighting to immovable concrete furniture, demands a working knowledge from electrical engineering to botany — all of which Morris readily acquired. What is missing at times is the discipline needed to keep the main themes of the story in focus. For all his quirks, Morris reminds us, Edison never lost sight of the future. And that, perhaps, is the key takeaway from this elegant, loosely crafted, idiosyncratic book. No inventor did more to nudge the world toward modernity, and few had a better feel for what the next generation of inventors might pursue.