Nebraska Academy of Sciences


Date of this Version



Published in Transactions of the Nebraska Academy of Sciences, Volume 4 (1977).


Copyright 1977 by the Authors; used by permission of the NAS


Aristotle, writing in the fourth century B.C., defined rhetoric as the "faculty of discovering in the particular case what are the available means of persuasion" (Aristotle, 1932, 1:2). He then proceeded to classify proofs intrinsic to the art of speaking into three modes-logos, ethos, and pathos. Consistent with his ''scientific'' point of view, he deplored writers of the arts of speaking who ignored argument; and his treatise emphasized the logical element in persuasion. As he said, persuasion is "effected by the arguments, when we demonstrate the truth, real or apparent, by such means as inhere in particular cases" (Aristotle, 1:2). That the purpose of much public, popular discourse throughout the ages has been to persuade or convince is obvious. However, the question of how the speaker or writer is to establish belief in his proposition and, in addition, appeal to the emotional and, imaginative side of his audience has offered much scope for theorizing among rhetoricians. Naturally, as conceptions of human knowledge and human nature changed, theories of suasory discourse changed, too. Not all later rhetoricians agreed with Aristotle that enthymematic reasoning formed the body and substance of persuasion.