I can't call a person a hard worker just because I hear they read and write even if working at it all night. Until I know what a person is working for, I can't deem them industrious...I can if the end they work for is their own ruling principle, having it be and remain in constant harmony with Nature.

—Epictetus, Discourses, 4.4.41;43 (resource) Ryan Holiday, The Daily Stoic