Discourse Conditions for Conditional Perfection: Extending Beyond QUDs

Abstract

This paper develops an account of conditional perfection (CP), the inference that strengthens conditionals from sufficiency (if p, q) to necessity and sufficiency (if and only if p, q). CP follows clear patterns across speech acts: it reliably occurs in inducements, varies in assertions, and is absent in advice (Van Canegem-Ardijns and Van Belle, 2008). I argue that this distribution follows from two discourse conditions: (1) the Exhaustivity Condition (speakers provide complete specification of sufficient conditions) and (2) the Epistemic Authority Condition (speakers are well-positioned to make exhaustive claims). Unlike previous accounts that tie exhaustivity to Questions Under Discussion (von Fintel, 2001), I propose that speech acts themselves structure discourse to satisfy or block these conditions. Commitment-based conditionals impose asymmetric discourse structures that guarantee both conditions, thus reliably triggering CP. Assertions satisfy these conditions only in specific contexts, while advice systematically resists CP by identifying possibilities rather than necessities. This framework explains inconsistent experimental results with QUD manipulations (Cariani and Rips, 2023; Grusdt et al., 2023) and offers a more comprehensive understanding of how diverse communicative functions can shape pragmatic inferences beyond purely informational contexts.