Leffingwell's Planet — Thomas J. Hubschman

A ship-wrecked space sailor is rescued by the oxygen-deprived inhabitants of a distant solar system. They treat him like royalty, but he soon realizes there is something fishy about Leffingwellians besides their appearance: Their culture is identical to that of Earth's two centuries earlier except for a peculiar state religion dedicated to a romance-novel goddess.

An attractive geophysicist uses his romantic interest to have him kidnapped by a band of revolutionaries, part of a planet-wide movement dedicated to overthrowing the Leffingwellian establishment, a color-coded society strangely like the old Earth's. He escapes into a surreal wilderness, is rescued by a blue-green siren, and in the midst of civil war unravels the mystery of the goddess Leffingwell and her planet's bizarre and forbidding fate.

By the author of the acclaimed Space Ark.