Enthymematic Arguments

Abstract

Enthymematic arguments are arguments appropriately appraised by a deductive standard whose premiss or premisses are partially topically relevant to their conclusion. The author of an enthymematic argument implicitly assumes the truth of a universal generalization of the argument’s associated conditional with respect to one or more content expressions which occur more than once. Unless it would be implausible, where a molecular content expression is repeated, this generalization is over the most molecular repeated content expression. If more than one distinct content expression is repeated, this generalization is over all such distinct content expressions except those over which it would be implausible to generalize. Unless the context of utterance of the argument or considerations of plausibility indicate a restriction, the generalization is over the entire category of items within which the content expression’s significatum occurs. This assumption is better regarded as a non-formal rule of inference than as a missing premiss. If it has exceptions, the argument is not enthymematically valid. Interpreters of philosophical arguments supplement them with such premisses for purposes other than evaluation: to understand why the author drew the conclusion, to strengthen the argument, to get support for their own position, or to discredit the argument.

Bibliographical note: This chapter was first published under the same title in Informal Logic 7 (1985), 83–97. An earlier version was presented at the Conference on Argumentation 1986 in Amsterdam, and published under the same title in Argumentation across the lines of discipline: Proceedings of the Conference on Argumentation 1986, ed. Frans H. van Eemeren, Rob Grootendorst, J. Anthony Blair, and Charles A. Willard, 289–298 (Dordrecht: Foris, 1987). The publication year in Informal Logic is misleading; the issue in which the chapter appeared was in fact printed in late 1986.