Understanding Causal Inference (David Papineau)

The Logic and Metaphysics Workshop will meet on March 7th from 4:15-6:15 (NY time) in-person at the Graduate Center (Room 5382) for a talk by David Papineau (King’s).

Title: Understanding Causal Inference

Abstract: The current pandemic has focused attention on the techniques used by epidemiologists and other non-experimental scientists to infer causal hypotheses from correlational data. These techniques, which hinge on assumptions about the way causal connections manifest themselves in conditional and unconditional correlations, pose an obvious philosophical challenge. What is it about causation that allows them to work? None of the mainstream accounts of causation—counterfactual, process, dispositional, regularity—casts any light on this question. Probabilistic and interventionist theories of causation do offer a direct response to the challenge, by positing a constitutive connection between causes and correlations, but I shall argue that these theories do not dig deep enough. Instead I shall develop an older idea—which goes back to H.A. Simon in the 1950s—that relates causal relationships to systems of structural equations with probabilistically independent exogenous variables. The attraction of this structural equations approach is that it allows us to view the correlational patterns as fallible evidence for causal relationships, rather than constitutive of them. I shall consider whether this approach can lead to a full reduction of causation and how it might accommodate quantum mechanical unpredictability.

Ignorance as an excuse, formally (Ekaterina Kubyshkina)

The Logic and Metaphysics Workshop will meet on February 14th from 4:15-6:15 (NY time) via Zoom for a talk by Ekaterina Kubyshkina (Campinas).

Title: Ignorance as an excuse, formally

Abstract: In the current literature on epistemology there is a lively debate on which type of ignorance may provide a moral excuse. A good candidate is the one in which an agent has never considered or thought about a true proposition p. From a logical perspective, it is usual to model situations involving ignorance by means of epistemic logic. However, no formal analysis was provided for ignorance as an excuse. First, we will argue that if ignorance is expressed via standard modalities of knowledge and belief, one is unable to represent ignorance as an excuse. Secondly, we fill this gap by providing an original logical setting for modelling this type of ignorance. In particular, we introduce a complete and sound logic in which ignorance is expressed as a primitive modality. Semantically, the logic is characterized by Kripke semantics with possibly incomplete worlds. Moreover, in order to consider the conditions of a possible change of an agent’s ignorance, we will extend the setting by considering public announcements.

Frame Definability in Finitely-Valued Modal Logics (Guillermo Badia)

The Logic and Metaphysics Workshop will meet on February 7th from 4:15-6:15 (NY time) via Zoom for a talk by Guillermo Badia (Queensland).

Title: Frame Definability in Finitely-Valued Modal Logics

Abstract: In this paper we study frame definability in finitely-valued modal logics and establish two main results via suitable translations: (1) in finitely-valued modal logics one cannot define more classes of frames than are already definable in classical modal logic, and (2) a large family of finitely-valued modal logics define exactly the same classes of frames as classical modal logic (including modal logics based on finite Heyting and MV-algebras). In this way one may observe, for example, that the celebrated Goldblatt–Thomason theorem applies immediately to these logics. In particular, we obtain the central result from [B. Teheux. Modal definability for Łukasiewicz validity relations. Studia Logica 104 (2): 343–363 (2016)] with a much simpler proof and answer one of the open questions left in that paper. Moreover, the proposed translations allow us to determine the computational complexity of a big class of finitely-valued modal logics.

Note: This is joint work with Carles Noguera and Xavier Caicedo.

Spring 2022 Schedule

The Logic and Metaphysics Workshop will be meeting on Mondays from 4:15 to 6:15 (NY time). Talks may be both virtual and in-person (at the Graduate Center, Room 5382); the details will be announced for each talk individually. The provisional schedule is as follows:

Feb 7. Guillermo Badia (Queensland)

Feb 14. Ekaterina Kubyshkina (Campinas)

Feb 21. NO MEETING

Feb 28. Michael Burton (Yale)

Mar 7. David Papineau (King’s)

Mar 14. Wilfrid Hodges (Queen Mary)

Mar 21. Noson Yanofsky (CUNY)

Mar 28. Dongwoo Kim (CUNY)

Apr 4. Jenn McDonald (Columbia)

Apr 11. Justin Bledin (Johns Hopkins)

Apr 18. NO MEETING

Apr 25. Tore Fjetland Øgaard (Bergen)

May 2. Elia Zardini (Madrid)

May 9. Friederike Moltmann (CNRS Nice) Julian Schlöder (UConn)

May 16. Mircea Dumitru (Bucharest)

 

Singular existentials and three different kinds of negation (Dolf Rami)

The Logic and Metaphysics Workshop will meet on December 13th from 4:15-6:15 (NY time) via Zoom for a talk by Dolf Rami (Bochum).

Title: Singular existentials and three different kinds of negation

Abstract: In this paper, I will argue for a new semantic analysis of (i) singular existential and (ii) atomic sentences to be able to cover three possible types of negation of them. Firstly, I will show that all three negations of sentences of kind (i) are equivalent if we make use of referring or non-referring names, while on the other hand the three negations of sentences of kind (ii) have several non-equivalent readings if non- referring names are used. Secondly, I will review the partial solutions to our problem given by Russell, Quine and Sainsbury and show in how far they fail. Thirdly, I will propose an alternative solution based on a semantics outlined in Rami (2020). Finally, I will show that we must distinguish two types of negation and that a unification in both directions fails.

Every Logic has its Proper Semantics (Diderik Batens)

The Logic and Metaphysics Workshop will meet on December 6th from 4:15-6:15 (NY time) via Zoom for a talk by Diderik Batens (Ghent).

Title: Every Logic has its Proper Semantics

Abstract: Many logics are sound and complete with respect to a multiplicity of semantic systems. These assign different sets of models to the logic. It will be shown that a series of problems result if all these semantic systems are on a par. I shall present a method to define a unique ‘proper’ semantics for the members of a huge class of logics, containing all usual deductive logics, and argue (i) that the proper semantics is defined in terms of syntactic criteria and so depends fully on the logic, (ii) that there are philosophical arguments to consider a logic’s proper semantics as natural, for example it correctly describes the ‘situations’ that are possible according to the logic. This solves the problems mentioned previously. Implications for the discussion on inferentialism are obvious. For some logics, the proper semantics coincides with the Henkin semantics. For other logics L, the proper semantics counts more models than the Henkin semantics: moreover, not all Henkin models are maximally L-non-trivial. A small change to the Henkin method has the effect that, for every logic L, the Henkin semantics coincides with the proper semantics.

Dualism About Generality (Martin Pleitz)

The Logic and Metaphysics Workshop will meet on November 29th from 4:15-6:15 (NY time) via Zoom for a talk by Martin Pleitz (Münster).

Title: Dualism about Generality

Abstract: In my talk I will motivate, outline, and apply a variant of first order predicate logic that can distinguish between two kinds of generality, which I call objectual generality and conceptual generality. To see the difference, compare the two general statements ‘Every human is a featherless biped’ and ‘Every human is a rational animal’. On a charitable understanding, the first sentence is about all humans past and present, as a subcollection of all particular objects currently accessible to us, while the second sentence is not about any particular object at all, but about the interaction of the concepts of being human and being a rational animal. Historically, the quantified sentences of predicate logic have been understood in either of the two ways. Frege understood them as expressing conceptual generalities; hence it was natural for him to call his predicate logic a “Concept Script”. Today, they are usually understood as objectual generalities, manifest both in the idea that a quantified sentence is like a conjunction (or disjunction) of its instances and in the current model theoretic orientation in semantics. But as we can find ourselves in a situation where we want to talk about both kinds of generality (and their interaction), it is worthwhile to develop the resources to express them within a single system. I will outline such a system that results from adding a second pair of quantifiers to regular first order predicate logic, and sketch applications to the notion of analyticity, natural kind predicates, and the ontological argument.

Similarity through indistinguishability: the geodesic reasoning on Kripke models (Konstantinos Georgatos)

The Logic and Metaphysics Workshop will meet on November 22nd from 4:15-6:15 (NY time) via Zoom for a talk by Konstantinos Georgatos (John Jay).

Title: Similarity through indistinguishability: the geodesic reasoning on Kripke models

Abstract: Several logical operators, such as conditionals, revision, and merge, are often understood through the selection of most similar worlds. In applications, similarity is expressed with distance and “most similar” translates to “closest” using a distance metric. We shall argue that similarity may arise through an indistinguishability relation between possible worlds and employ the geodesic distance of such a model to measure closeness. This understanding allows us to define a variety of operators that correspond to merging and revising. I will present a few systems and representation results and will show that revision, merging, and conditioning are interdefinable thus, in effect, satisfying the Ramsey test.

The Subject-Matter of Modal Sentences (Thomas Macaulay Ferguson)

The Logic and Metaphysics Workshop will meet on November 1st from 4:15-6:15 (NY time) via Zoom for a talk by Thomas Macaulay Ferguson (University of Amsterdam).

Title: The Subject-Matter of Modal Sentences

Abstract: The framework of topic-sensitive intentional modal operators (TSIMs) described by Berto provides a general platform for representing agents’ intentional states of various kinds. For example, a TSIM can model doxastic states, capturing a notion that given the acceptance of antecedent information P, an agent will have a consequent belief Q. Notably, the truth conditions for TSIMs include a subject-matter filter so that the topic of the consequent Q must be “included” within that of the antecedent. To extend the account to languages with richer expressivity thus requires an expanded account of subject-matter. In this talk, I will discuss extending earlier work on the subject-matter of intensional conditionals to the special case of modal sentences whose primary operators are interpreted by possible worlds semantics.

Regrounding the Unworldly: Pluralism and Politics in Carnap’s Philosophy of Logic (Noah Friedman-Biglin)

The Logic and Metaphysics Workshop will meet on October 25th from 4:15-6:15 (NY time) via Zoom for a talk by Noah Friedman-Biglin (San José State University).

Title: Regrounding the Unworldly: Pluralism and Politics in Carnap’s Philosophy of Logic

Abstract: The locus classicus of logical pluralism – that is, the view that there is more than on logic, properly so called – since the earliest days of analytic philosophy, can be found in Rudolf Carnap’s ‘principle of tolerance’. Clarifying the principle of tolerance is the focus of this first section of this paper. I will argue that the principle should be understood as widely as possible, and thus we will see that Carnap’s tolerance is a very radical view. In section two, I discuss the motivations Carnap had for his pluralism, and argue that they are based in the Vienna Circle’s “Scientific World-Conception” — a platform of philosophical commitments which set the direction for the Circle’s philosophical investigations as well as a program of social change. What emerges from this discussion is the often-ignored relationship between his logical pluralism and his political views. In short, I will argue that the radical quality of his tolerance is due to these political commitments. In section three, I examine the reasons why this connection is not very well-known. I will argue that the political situation in the United States in the aftermath of World War 2 created conditions where it was dangerous to explicitly link scholarly work and politics, and discuss the reasons that Carnap might have had for distancing himself from – or at least de-emphasizing – the political foundations of his views.

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