The ability to speak clearly, eloquently, and effectively has been recognized as the hallmark of an educated person since the beginning of recorded history. Systematic written commentary on how to develop this ability goes back at least as far as The Precepts of Kagemni and Ptah-Hotep (3200-2800 B. C. E.). This document, the oldest remnant of the Egyptian Wisdom Books of the Middle and New Kingdoms (used as a manual of advice to train individuals headed for positions as scribes and officials), contains forty-five maxims, one-third of which are related to effective communication, such as (1) keep silent unless there is something worth saying, (2) wait for the right moment to say it, (3) restrain passionate words when speaking, (4) speak fluently but with great deliberation, and (5) above all, keep the tongue at one with the heart so the truth is always spoken.

Under the label of "rhetoric," the theory...