It is helpful to write always at the same time of day. Scheduled obligations often raise problems, but an hour or two can almost always be found in the early morning-when the telephone never rings and no one knocks at the door. And it is important that you write something, regardless of quantity, every day. As the Romans put it, Nulla dies sine linea-Noday without a line. (They were speaking of lines drawn by artists, but the rule applies as well to the writer.) As a result of all this, the setting almost automatically evokes verbal behavior. No warm-up is needed. A circadian rhythm develops that is extremely powerful. At a certain time every day, you will be highly disposed to engage in serious verbal behavior.

B.F. SKINNER