Quote by Joseph Addison, "The Spectator",
Authors have established it as a kind of rule, that a man ought to be dull sometimes; as the most severe reader makes allowances for many rests and nodding places in a voluminous writer.
Summary
This quote suggests that authors have come to accept that occasional dullness is a necessary component of writing. Just as serious readers understand that a long book will have its moments of boredom and fatigue, authors too believe that they are allowed to have "rests and nodding places" in the midst of their otherwise engaging writing. It acknowledges the importance of pacing and recognizes that it is unrealistic to expect constant excitement and stimulation from any writer or piece of literature.