I notice that when all a man’s information is confined to the field in which he is working, the work is never as good as it ought to be. A man has to get a perspective, and he can get it from books or from people — preferably from both. This thing of sleeping and eating with your business can easily be overdone; it is all well enough—usually necessary—in times of trouble but as a steady diet it does not make for good business; a man ought now and then to get far enough away to have a look at himself and his affairs.

— Harvey S. Firestone (written in 1926) (T/H to Farnam Street)