Epistemic Modality and Authority: An Interactional Approach

Sherman Brett

University of South Carolina

 

Elaine Chun

University of South Carolina

 

When is it appropriate to use an epistemic necessity modal, as in (1), as opposed to the bare prejacent, as in (2)?

 

(1) His lungs must be bleeding.

 

(2) His lungs are bleeding.

 

Common to recent work on this question (for example, von Fintel and Gillies 2010, Lassiter 2014, Matthewson 2015) is the idea that the difference in appropriateness is a function of some aspect of the speaker's evidence in support of the prejacent. In this paper, we argue instead that the difference concerns whether the speaker leaves the question under discussion on the table or treats it as settled (cf. Roberts 2012).

 

Central to our argument is the claim that evidence alone does not determine whether a question is open or settled, even when one’s evidence eliminates all but one answer. One must also trust that there are no additional possibilities, and that one’s evidence legitimately eliminates the alternatives. Accordingly, the greater one’s position of epistemic authority, the more likely one is to treat the question as settled.

 

On the assumption that the presence or absence of trust will vary among interactional participants who are subject to the same evidence, but occupy different positions of epistemic authority, our hypothesis is that an utterance of the bare prejacent will be more common than the corresponding must statement among those with a higher position of epistemic authority.

 

We test this hypothesis by analyzing 50 examples drawn from corpora of naturally occurring and scripted interactional data. For example, in the following excerpt from House (2005) in which two doctors aim to diagnose a patient, they leave open the question of whether there is bleeding around the patient’s heart when addressing one other (lines 3a and 3b), yet when addressing the patient (line 3c), treat the question as settled, despite consistent evidence across these utterances.

 

(3a)

CAMERON: Neck veins are out; must be pericardial effusion.

(3b)

FOREMAN: Tear in his lungs must have re-opened.

(3c)

CAMERON: Kalvin, you’re bleeding into the area around your heart.

 

By examining interactions and their sequential organization of utterances (Sacks, Schegloff, and Jefferson 1974), we illustrate how participants negotiate their relative positions of authority whether by settling questions under discussion, by leaving questions open, or by challenging prior attempts to settle questions.