Man is so made that he can only find relaxation from one kind of labor by taking up another.

The remark treats “rest” not as pure idleness but as a change of occupation. France suggests that human beings are structured to seek relief from strain by redirecting their energies—mental to physical work, solitary to social tasks, routine to creative effort—rather than by stopping altogether. The idea implies a restless, adaptive psychology: satisfaction comes from variety and renewed purpose, and boredom or fatigue often signals not that all effort is intolerable, but that a particular kind of effort has been overdrawn. It also carries a quiet critique of leisure as mere inactivity, proposing instead that renewal is found in meaningful alternate labor.