Keith Laumer, A trace of memory (1962)
“ There's nothing like a little slavery to make a man appreciate even a modest portion of freedom. Everything I had thought I knew about Vallon had been wrong: the centuries that passed had changed things—and not for the better. The old society that Foster knew was dead and buried. The old places and villas lay deserted, the spaceports unused. And the old system of memory-recording that Foster described was lost and forgotten. I didn't know what kind of a cataclysm could have plunged the seat of a galactic empire back into feudal darkness—but it had happened. ”
