Rhetorical Situation and Kairos
Lloyd F. Bitzer described the concept of the rhetorical situation in his essay of the same name.1 The concept relies on understanding a moment called "exigence," in which something happens, or fails to happen, that compels one to speak out. For example, if the local school board fires a popular principal, a sympathetic parent might then be compelled to take the microphone at the meeting and/or write a letter to the editor. Bitzer defined the rhetorical situation as the "complex of persons, events, objects, and relations presenting an actual or potential exigence which can be completely or partially removed if discourse, introduced into the situation, can so constrain human decision or action as to bring about the significant modification of the exigence."
Some elements of the rhetorical situation include:
Analyzing the rhetorical situation (which, at its most fundamental, means identifying the elements above) can tell us much about speakers, their situations, and their persuasive intentions.
The ancient Greeks gave special attention to timing--the "when" of the rhetorical situation. They called this kairos, and it identifies the combination of the "right" moment to speak and the "right" way (or proportion) to speak. Let's get back to the school board example. After voting to fire the popular principal, the sympathetic parent might grab the microphone and scream invectives at the board. This would be bad kairos. Perhaps a better choice would be to recognize that a mild rebuke fits the situation followed by a well-timed letter to the editor or column in the school newsletter.
1: Bitzer, Lloyd F. 1968. "The Rhetorical Situation." Rhetoric: Concepts, Definitions, Boundaries. William A. Covino ed. Boston: Allyn and Bacon: 1995.