Monotonicity via mereology in the semantics of attitude reports

In this paper, we develop a new proposal about how the monotonicity of attitude verbs like believe should be modeled within the content-based approach to clausal embedding (Kratzer 2006, 2013). We pursue the idea that monotonicity is a consequence of how the part-whole structure of attitudinal eventualities relates to the part-whole structure of their contents and thematic participants. In order to cash out this idea, we rely on a non-monotonic, equality-based implementation of the content-based approach (Moulton 2009, Elliott 2020, 2017, Bassi & Bondarenko 2022), supplemented with tools and concepts from mereology. We apply the mereological account of monotonicity to a pattern noticed by Sharvit (2024) concerning Negative Polarity Item (NPI) licensing in nominal arguments to monotonic attitude verbs, which existing implementations of the content-based framework fail to capture.