This article also references about four hours as the limit that a creative professional can work every day: http://nautil.us/issue/46/balance/darwin-was-a-slac

This article also references about four hours as the limit that a creative professional can work every day: http://nautil.us/issue/46/balance/darwin-was-a-slacker-and-you-should-be-too http://nautil.us/issue/46/balance/darwin-was-a-slacker-and-y...