Workshop on Vagueness

Weak Denial in Layered Discourse Representation Theory

Abstract: In this paper, the treatment of denial in layered discourse representation theory (LDRT) is revisited. In LDRT, denial reduces contextual content, whereas multilateralists identify weak denial, a speech act that blocks the addition of content without removing any. We show that LDRT undercounts such cases: new content is blocked from becoming a common belief, yet it cannot be easily removed when reasons remain unspecified. Drawing on multilateralist insights, we recast the contextual effect of denial in LDRT as update-blocking and treat the star condition as its formal marker, ensuring that weak denial is represented as having occurred even before any withdrawal. This preserves LDRT’s representational virtues while closing its explanatory gap.

Keywords: Discourse Representation Theory; Denial; Speech Acts; Informal Reasoning

Ibn Sı̄nā’s Burhān Al-Ṣidiqīn

Abstract: One of the most important of Ibn Sīnā’s innovations in the history of Western philosophy was an argument for the existence of a necessary existent (wajīb al-wajūd). The argument is known as the burhān al-ṣiddiqīn (demonstration of the truthful). In this talk I analyse and evaluate the burhān using the tools of contemporary logic and mereology.

Two Objections to a Dialetheic Solution to the Semantic Paradoxes

Abstract: Saul Kripke’s 1975 paper on truth marked a turning point in research on the semantic paradoxes towards languages which contain their own truth predicate. One such approach is a dialetheic one. In my experience, the two most common objections to this (other than a blanket rejection of dialetheism) concern (a) Curry’s paradox, and (b) the “truth-only” problem. I find neither of these persuasive. In this talk I will explain why.