Conquering Our Imagination: Thought Experiments and Enthymemes in Scientific Argument

Abstract

The dividing line between rhetoric and science has traditionally been drawn at the split between persuasion and logic. On the one side, rhetoric seeks to influence human beliefs and behavior through use of stylistic language that resonates with the experiences of an audience; on the other, science endeavors to describe empirical phenomena through the use of logical propositions that can be understood wholly on their own terms. However, recent scholarship has blurred this border. For instance, in his research on Charles Darwin's rhetorical accomplishments, John Angus Campbell has sought to break down "the neopositivist Berlin Wall separating the context of discovery from the context of justification" that represents this traditional division (1990, 23). Claiming that scientific discovery and rhetorical invention are each "an aspect of a flexible logic of inquiry and presentation" (23), Campbell argues that "the social and theological ring of Darwin's language is not merely decorative or ameliorative, but is constitutive of the fabric of his thought" (5). In other words, Campbell insists there is something intrinsically valuable about Darwin's frequent use of colloquial language beyond its immediate rhetorical appeal—it also contributes something fundamental to scientific knowledge itself.