Emphyrio — Jack Vance

Halma ...where humans were ruled by a race of effete and arrogant Lords...where a feudalistic system banned all work by machines...where a "benevolent" welfare state rewarded talented hand labor with a barely adequate sustaining dole...

Young Ghyl Tarvok, fascinated by the legend of Emphyrio, became a rebel. In a pirated space ship, he began his search through the civilizations of neighboring planets for the key to the origin of his home world's culture and the secret that might change it. Inexorably he moved toward the last desperate hope: the planet his ancestors had left many thousands of years before--the mysterious and terrifying place called Earth.