## Zoom links: Day 1 Day 2 Day 3

## Invited speakers

**Singa Behrens **(Hamburg University) – Zoom

*Partial Irrelevance and Exact Exclusion.*

In this talk, I discuss a truthmaker-based account of partially irrelevant conclusions in terms of *exact exclusion*. I argue that extant accounts that are based on a notion of *non-difference making* parts overgenerate. They are based on minimality requirements that are too strict because they exclude cases of overdetermination. In response, I propose an alternative account that is based on a relation of exact exclusion between states. The account can do justice to cases of overdetermination. A primitive, but constrained relation of exclusion was first introduced in (Fine 2017). I define a notion of exact exclusion based on Yablo’s recent account of proportionality without minimality (Yablo forthcoming). I show that the truthmaker-based account of partial irrelevance provides the means to explain complications in other debates that result from partially irrelevant conclusions.

**Stephan Krämer** (University of Hamburg)

*Negation by Limitation*

I propose a novel truthmaker account of negation, employing what I call limitation-states. When some state s part of another t, I postulate a limitation-state to the effect that as far as parts of s are concerned, at most t (and any part of t) obtains. One might regard such a state as obtained from a totality state – as far as parts of s are concerned, t obtains, and that’s all – by subtracting the condition that the smaller state s obtains. The basic idea is that verifiers of not-P take this form: as far as the subject matter P is concerned, at most s obtains, where s is any part of the subject matter of P not containing a verifier of P. I show that under certain assumptions, the resulting account validates the DeMorgan laws and the identity of P to not-not-P.

**Hannes Leitgeb** (LMU Munich) – Zoom

*On the Logic of Vector Space Models*

This talk will introduce and study logical systems in which formulas represent “effects” (e.g. of argumentation), such that these “effects” correspond formally to vectors. In a slogan: content is a vector. The logics involve deductive systems, semantics with appropriate notions of logical consequence, and extensions to similarity, inductive logic, and belief revision. The resulting systems may be interpreted in probabilistic terms, and they can be applied to logically reconstruct and address some well-known problems and methods from philosophy, cognitive psychology, computational linguistics, and machine learning, including problems and methods concerning explanatory reasoning.

**Jon Litland** (University of Texas at Austin & University of Oslo) – Zoom

*General Subject Matter*

In truthmaker semantics the subject matter of a proposition is taken to be a single state – the fusion of all the truthmakers and falsemakers of the proposition. This account works beautifully for the truth-functional operations but breaks down for quantified propositions. The account incorrectly predicts that the proposition that someone is wise is partly about Socrates. In this talk I develop a novel account of subject matter that can account for the subject matter of quantified propositions. The basic idea is that the subject matter of a proposition is taken to a collection of states – the subject matter of the proposition should be thought of as what is common to those states

**Ed Mares** (Victoria University of Wellington) – Zoom

*Theories and Nested Entailments*

**Joke Meheus** (Ghent University)

*Logics for explanatory coherence relations*

**Francesca Poggiolesi** (IHPST, UMR 8590, CNRS & Université Paris 1 Panthéon-Sorbonne) – Zoom

*Conceptual grounding and conceptual explanation … It is not complicated!*

In this talk we analyse in detail the relations between two kindred notions, namely conceptual grounding and conceptual explanation.

**Martin Pleitz** (independent scholar)

*Ground and Construction*

Ground and construction provide a static and a dynamic explication of metaphysical structure. Both present connections of relevance, with ground being an explanatory *hierarchy *among facts and construction a creative *process *of making new objects based on older items. My talk relates the two. At ExLog 2019, I had argued that to prevent paradox we should require metaphysical grounding to be well-founded. To supplement this regressive reasoning, I now outline a theory of **construction by reification**. Reification associates a non-objectual item with an object that encodes it. Reification claims can be expressed in a non-self-undermining way with encoding operators and associated decoding predicates. Depending on its existence claims, reification is static or dynamic. It accounts for all abstract objects, from numbers and sets via facts and properties to words. But as befits a conference of hyperintensional bent, I illustrate construction by reification mainly with a case study on **making truthmakers**. We move from grounding to truthmaking facts by a process of *two-fold *reification, delivering states and sentences connected by the decoding *relation *of truthmaking. This turns the tables between truthmaker semantics and grounding logic and elucidates paradoxes of truth and truthmaking. These occur when reification is static and are precluded when reification is dynamic. This diagnosis and therapy generalize to a uniform approach to the semantic and set theoretic paradoxes. Which brings us back to **the structure of ground**, observing that any process of construction by reification leaves a trace of well-founded grounding. But is *all *ground just constructional residue?

**Andrew Tedder** (Department of Philosophy I, Ruhr University Bochum)

*Situations, Propositions, and Information States*

In this talk I’ll employ results showing that the Ternary Relation (“Routley-Meyer”) and Operational-Relational (“Fine”) semantics for relevant logics are equivalent in order to assess which style of account provides a better explanation of facts about logical consequence. This is of interest because of the apparent divergence in the use of these two frameworks for various non-classical logics, especially in recent years. The main upshot is that the construction employed in the equivalence proofs give rise to a choice between two different three-layered semantic pictures, incorporating both the TR and O-R semantics. I’ll argue that of these two three-layer pictures, the one which grounds out in a realistically construed TR style semantics is preferable, while still providing us the advantages of the O-R style semantics. I’ll discuss upshots of this argument, and directions for future research tying together semantic theories employing these two frameworks.

## Contributing speakers

**Alessandro Cecconi** (University of Geneva)

*To Be Done with All this Measuring of Truth* abstract

**Matthieu Fontaine** (Universidad de Sevilla) & **Cristina Barés** (Universidad de Sevilla)

*Freedom, Commitment, and Abductive Hypotheses in Dialogical Logic* abstract

**Martin Grajner** (Dresden University of Technology)

*Quantifiers, Grounds, and Ontological Commitment* abstract

**Jose Antonio Perez Escobar** (École Normale Supérieure, Paris Sciences et Lettes University) – Zoom

*Challenging the relevance of mathematical counterfactuals in biology* abstract

**C. Naomi Osorio-Kupferblum** (University of Vienna)

*Translating true ways* abstract

**Pierre Saint-Germier** (Université catholique de Louvain)

*Relevant entailment, difference-making, and logical ground*

**Vera Shumilina** (HSE University Moscow) – Zoom

*Against Unifying Continuum-View of Scientific and Metaphysical Explanations* abstract

**Andrés Soria-Ruiz** (ArgLab, IFILNOVA, Lisbon) – Zoom

*Modal semantics for causal explanations* abstract

**Anthony Stoner** (UC Riverside) – Zoom

*About the translation of I.E. Orlov’s 1928 “Calculus of the Compatibility of Sentences”*

**Pilar Terrés** (University of Barcelona and Université catholique de Louvain)

*Meaning postulates for substructural languages* abstract

**Peter Verdée** (Université catholique de Louvain)

*Ground-theoretic* *semantics*