The Variable Man by Philip K. Dick, Science Fiction, Literary, Fantasy

The Terran system is growing and expanding all the time. But an old and corrupt Centaurian Empire is holding Terra down, as it encircles the Terran system and will not let the humans grow out of their current empire. For this reason Terra is at war with Proxima Centauri and is trying to find a way of breaking free from the Centaurian's hold upon them. Thomas Cole escapes from the authority in the future and spends a lot of time running from them afterwards. It is, however, discovered that this man has a certain genius to fix things and make things work. This is because he comes out of a period of time when humans had a natural genius and an ability to invent things and to solve problems. He fixed things -- clocks, refrigerators, vidsenders and destinies. But he had no business in the future, where the calculators could not handle him. He was Earth's only hope -- and its certain failure!