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.