The monotonous speaker not only drones along in the same volume and pitch of tone but uses always the same emphasis, the same speed, the same thoughts—or dispenses with thought altogether.
Monotony, the cardinal and most common sin of the public speaker, is not a transgression—it is rather a sin of omission, for it consists in living up to the confession of the Prayer Book: "We have left undone those things we ought to have done."
Emerson says, "The virtue of art lies in detachment, in sequestering one object from the embarrassing variety." That is just what the monotonous speaker fails to do—he does not detach one thought or phrase from another, they are all expressed in the same manner.