The Epistemic Stance and the Rhetorical Stance: A Frequency Analysis of Modal Verb Usage and Rhetorical Technique in Expert Witness Testimony

To some Americans, the recent movements against Critical Race Theory, masks, and vaccine mandates might seem like unprecedented attacks on expertise. To those familiar with the discourse of the anti-evolution, creation science, and intelligent design movements, however, these three ongoing disputes represent only the latest episodes in Americans’ century-long public dispute over the increasing role of experts in setting the terms of public discourse. In this dissertation, I offer a word frequency analysis of epistemic modal verb usage in expert witness testimony in Scopes v. Tennessee, McLean v. Arkansas, and Kitzmiller v. Dover, three legal cases born out of the century-long conflict over the role of evolution, anti-evolutionism, creation science, and intelligent design in public school science classrooms. In doing so, I synthesize recent research in rhetoric, philosophy, and linguistics with the concept of the “rhetorical stance” and illustrate how modal verbs, as a grammatical feature of English, contribute to the construction of what I call the “anti-expert,” “counter-expert,” and “para-expert” rhetorical stances. As I will show, each of these three stances deploy modal verbs to modulate rhetors’ expressed level of certainty in their statements, helping them to establish their own expertise or attack that of others.