Metaphors are deemed to have rhetorical potential. In what way and to what extent they affect argumentative discourse is, however, not entirely clear. This presentation discusses the results of an empirical study on the effect of the metaphor presence on the evaluation of sound and fallacious argumentation.
Metaphors are deemed to have rhetorical potential. In what way and to what extent they affect argumentative discourse is, however, not entirely clear; results of previous experimental research on metaphors in argumentation are mixed. The effect that metaphor has on argumentation might depend on the quality of the argumentation that is presented by means of it. Metaphors can highlight or hide particular aspect of a message, so a metaphor could, for example, highlight the goodness of sound argumentation and the badness of fallacious argumentation. The central question in this presentation is therefore: how exactly does the presence of metaphor influence the evaluation of sound and fallacious argumentation? To answer this question, we conducted an experiment in which we asked respondents to evaluate dialogue fragments in which novel, direct metaphors were used to present a premise of the argumentation. These novel, direct metaphors were used to make sure that respondents processed the metaphors as metaphors, and that this processing was essential for understanding the argumentation. Additionally, we manipulated the soundness of the argumentation to systematically explore whether there is an interaction between metaphor presence and argumentative quality. To do so, we used a two (with metaphor / without metaphor) by two (sound argumentation / fallacious argumentation) multiple-message, repeated-measures design. The experiment shows that the presence of a novel, direct metaphor negatively affects the reasonableness evaluation of argumentation. Additionally, it shows that the extent of this effect depends on an interaction between soundness and metaphor presence: fallacious arguments are less affected by metaphor presence than sound arguments. This result goes against the general conception that metaphor positively influences argument evaluation. It also provides us with a possible explanation for the mixed results obtained in previous effect studies.
