Simak Clifford. The Werewolf Principle

Andrew Blake is found in a space capsule on a distant planet and is brought back to an unfamiliar Earth, where antigravity devices have replaced the wheel, and houses talk and even fly!
Yet nothing is as strange as Blake's own feelings. Tormented by eerie sensations and loss of memory, he doesn't know who he really is or exactly where he has come from. His destiny only begins to grow frighteningly clear when he meets a weird, tassel-eared creature who darkly hints at the truth about Blake's origins. Slowly Blake becomes aware of the long hushed-up "Werewolf Principle," a scientific theory buried in the past, which holds the key to Blake's own fate-and the future of the human species.-book cover