He had assumed that if you removed a human being's natural incentive to work—his initiative, his spontaneous creative energy—and replaced it with external motivation and coercion, he would become a lazy and careless worker. But no careless workers kept those lovely farmlands, or made the superb cars and comfortable trains. The lure and compulsion of profit was evidently a much more effective replacement of the natural initiative than he had been led to believe.

Chapter 3 (p. 82) - Hainish Cycle - The Dispossessed (1974)