§1. The debate on anti-exceptionalism about logic (AEL) asks whether logic is continuous with the sciences or exceptional in virtue of being special in sufficient relevant respects. Metaphysical AEL holds that logic’s subject matter is anti-exceptional. However, the appeal to continuity has been charged with being underspecified. In response, Hjortland and Martin (2022) offer a conceptually-engineered, tradition-based account: AEL is best understood as a cluster of views, united by the claim that logic either lacks some traditionally considered exceptional features or has them in an unexceptional form. §2. I argue that AEL requires an account of continuity. First, the tradition-based cluster account fails to capture what it is for logic to be anti-exceptional. Even if logic lacked all traditionally cited exceptional features, it could still be exceptional in another, as yet unidentified, respect. This would clearly be no basis to consider logic exceptional and not exceptional (because it is anti-exceptional, according to conceptually-engineered AEL). Moreover, consider the novel contribution to AEL by Russell (2023) who, on the ground of idealization in logic, defends a realism about its representational targets, such as predicates, and sentential truth. Since idealization is not traditionally discussed, her explicit contribution would not count as a contribution to AEL on their account. Second, drawing on linguistic work on gradable adjectives like ‘exceptional,’ I argue that any cluster account of AEL requires an account of how claims about particular features of logic support the claim that logic itself is anti-exceptional. For, even a cluster of views that treats every feature of logic as anti-exceptional in some respect does not automatically establish AEL, since not every property inherits upward from parts to wholes. What is thus needed, is an explanation of how these local claims jointly support the global claim that logic, as a discipline, is anti-exceptional. I argue that this requires an account of continuity. Third, I ask whether metaphysical AEL can be defended without continuity, and argue that it cannot. Metaphysical AEL holds that logic’s subject matter is anti-exceptional, not the discipline. But without restriction, this includes trivial claims (e.g. that it is the subject matter of a discipline), or non-trivial but uninteresting claims (e.g. that it is liked by me). Metaphysical AEL must therefore be restricted to the claim that logic’s subject matter is anti-exceptional with respect to being the subject matter of a scientific discipline. I argue that meeting this demand again requires an account of continuity. §3. In conclusion, metaphysical AEL requires a clear notion of continuity, one that is currently lacking. As it stands, AEL remains underdeveloped for supporting anti-exceptional claims about logic’s subject matter.

Logical Nihilism contends that for any purportedly valid inference, counterexamples can always be constructed; thus, there are no genuine logical constraints on natural language (see Estrada-González, 2011; Mortensen, 1989; Russell, 2018). Cotnoir (2018: 307–8) develops an argument in support of this view, targeting Lynch (2009)’s alethic and logical domain-based pluralism (DBP). On this account, truth is a higher-level property instantiated across domains via distinct truth-properties (Lynch, 2009: 70). If validity is understood as truth-preservation, the variation in truth-properties across domains motivates distinct consequence relations, possibly yielding logical DBP. Cotnoir contrasts DBP with the topic-neutrality of logic, according to which validity depends solely on form and not on content (Sher 2016). Since these two are incompatible, if DBP rejects topic-neutrality, validity becomes content-dependent, and logical nihilism follows. In this paper we resist Cotnoir’s argument by granting that DBP rejects topic-neutrality, while addressing whether this makes validity content-dependent. Indeed, DBP entails that logics are not topic-neutral, for they are constrained by the truth-property operative within each domain; nevertheless, the lack of topic-neutrality does not imply that validity is content-dependent. To yeld a more precise understanding of this, we develop a Generalized Tarski Thesis (GTT) tailored for DBP. By constraining how consequence relations are precisified, GTT guides the selection of the appropriate logic in a given domain. By this model, we show how DBP can preserve the formality of logic. Generalised Tarski Thesis for DBP: An argument is validd iff, in every cased in which the premises are trued, the conclusion is trued. d indicates the relevant domain-constraint. We introduce the structure L = ⟨dk, τc, τu⟩, where dk is the domain, and τc and τu denote the possible truth-properties—respectively, epistemically constrained and unconstrained—of premises and conclusion, thus introducing a corresponding notion of validityd. In cases of mixed inference, we extend this structure with a selection function δ, yielding L = ⟨dk, τc, τu, δ⟩. δ takes the premises’ truth-properties as input and returns the relevant truth-property for selecting the appropriate logic. In mixed inferences, δ always selects τc. Following Beall and Restall’s case-parameterization for GTT (Beall and Restall, 2005), we aim to explain how informational states in truth-preserving cases (e.g., complete Tarskian models or incomplete constructions) depend on the domain of inquiry and give rise to different relations of validity, while avoiding validity becoming content-dependent.

In this talk, I develop a new version of the thesis that model-theoretic logic is analytic. Logic has traditionally been regarded as paradigmatically analytic, but this status has been challenged by W. V. O. Quine’s attack on the analytic/synthetic distinction and by the rise of model-theoretic semantics. On the standard model-theoretic account, logical truth is defined as truth in all models, and logical consequence as truth- preservation across all models. It is therefore unclear how such notions could count as analytic, since their definitions do not appear to appeal to meaning in any substantive sense. Building on the work by Sánchez-Miguel (1993), I first diagnose a central weakness in his analyticity thesis: for logical truths, being true in virtue of the meaning of logical constants and true in all models are one and the same property. I argue that this equivalence is insufficiently grounded: it does not explain how truth in all models is itself determined by the meanings of logical constants. This failure stems from two sources. First, the notion of “all models” is purely extensional, offering no independent guarantee that the relevant class is properly delimited. Second, the account assumes that semantic clauses exhaust the meanings of logical constants, leaving no room to explain how those clauses are themselves justified. To bridge this gap, I propose shifting from an extensional to an intensional conception of meaning of logical constants. (a move proposed by Sagi (2014)) In place of quantification over all models, we should appeal to a restricted class of admissible models, determined by the intensional content of logical constants. On this view, the meanings of logical constants impose semantic constraints on what counts as a admissible model. These constraints ensure that logical constants denote truth-functions or isomorphism-invariant properties, thereby grounding logical consequence in meaning. Finally, I show how this account can be situated within a broadly correspondence truth theory framework. Logical truths arise from the joint contribution of meaning and fact, with meaning playing the primary role in fixing the relevant class of admissible models. Relatedly, this proposal also connects with Gillian Russell’s (2008) notion of metaphysical analyticity, according to which logical consequence’s analyticity depends on containment relations between reference-determiners. I make this idea more precise by identifying reference-determiners with the sets of models in which sentences are true. Logical consequence then corresponds to a set-theoretic inclusion relation: every model that makes the premises true also makes the conclusion true.

The thesis of this talk is that there is truth simpliciter and it has two aspects which need to be integrated. Firstly, one needs a minimal concept of truth which is a condition for all true statements. Secondly, truth simpliciter is not just a minimal concept and it must be brought back to its principle (ἀρχή) in an enquiry of teleological nature. Truth simpliciter, as put by Aristotle, does not hold just under a certain relation (Soph. El. 166b59–167a2). A further important point on truth simpliciter is that we can grasp it at best through fundamental principles (An. Post. I 71b9-12). Connected with the second point is the thesis that truth is a principle of our theoretical enquiry and that the ultimate truth is the final principle (τέλος) of our theoretical enquiry. Historically one can differentiate between two main groups of theories of truth which are still present in the discourse, namely objective truth theories based on the notion of correspondence (Russell 1967) or adequation (De veritate I, 1) and epistemic truth theories based especially on the notions of coherence (Blanshard 1941) and pragmatism (Peirce 1878; James 1907) but neither of these theories is unproblematic (Brendel 2017). Since Tarski’s formulation of the ‘equivalence of the form T’ in The Semantic Conception of Truth the connotation of truth simpliciter has often been associated with formal logical truth expressed through the equivalence of the form T (Tarski 1944). The correspondence is then between ‘descriptive expressions’ and ‘individuals’ or ‘objects’ in a domain of objects and if the equivalence is satisfied for all objects, it expresses a truth simpliciter. Another differentiation is made between inflationary and deflationary theories on truth. The deflationary positions reject the inflationary ones by denying that truth is not a substantive concept (Brendel 2017). Inflationary theories of truth are closer to the most adequate conception of truth simpliciter as truth that does not hold only in regard to certain relations and that has a teleological character. I will start from truth simpliciter from the point of view of inflationary, substantive theories of truth as those of minimal Normative Alethic Pluralism from Ferrari (2022) and Correspondence Pluralism from Sher (2017) to argue that truth simpliciter has a teleological character that goes even beyond that accepted in substantive theories of truth and objective theories of truth.

The paper examines how contemporary dialogical logic, as developed by Lorenzen and Lorenz, marks a shift from a truth-centered conception of validity to one centered on justification. It focuses on its philosophical roots (especially later Wittgenstein and intuitionism), highlighting the fundamental role of regulated interaction in determining meaning and validity. Logical validity emerges from intersubjective practices of argumentation rather than from purely formal or solitary proof structures. In contrast to the classical logical tradition, the most innovative feature of the dialogical logic developed by Paul Lorenzen and Kuno Lorenz lies in the introduction of an interactive perspective that interprets propositions as inseparable from the dialogical contexts in which they are used. This framework stands at the intersection of several philosophical traditions. A decisive role is played by the intuitionism of L. J. Brouwer, according to which logic is subordinate to the constructive activity of the mind. Lorenzen adopts some of its core assumptions – particularly the finiteness of procedures and the identification of existence with constructibility – while reformulating them in an operational and pragmatic key. This entails a revision of classical principles such as the law of excluded middle and double negation, in light of a conception of truth grounded in proof. At the same time, the influence of Edmund Husserl and the later Wittgenstein directs attention toward the relation between meaning and use, highlighting the public and intersubjective dimension of language. In this context, Lorenzen’s “protologic” aims to ground logic and mathematics on shared operational criteria, replacing appeals to self-evident axioms with procedures of controllable justification. This results in a dynamic conception of logic, opposed to the static view of the classical tradition. A proposition is intelligible only within a regulated, finite, and structured dialogue in which two interlocutors – the Proponent and the Opponent – engage according to explicit rules governing attacks and defenses. The meaning of logical constants thus emerges from their use within such practices. Validity no longer coincides with a solitary proof, but with the possibility of successfully sustaining a position within a regulated interaction – e.g. a claim is valid only if it can withstand all legitimate counterarguments. The intersubjective dimension of truth should therefore not be understood as contingent agreement, but as dependence on public procedures of justification. In this sense, Lorenzen’s reference to the ancient dialectical tradition is central: argumentation is not a solitary search for truth, but a regulated practice of rational confrontation. Depending on the normative-dialogical framework, one can distinguish more agonistic forms, oriented toward victory, and cooperative forms, aimed at clarifying conditions of validity. Dialogical logics thus emerge as a general theory of argumentative rationality, integrating formal, practical, and intersubjective dimensions.

In textbooks and research articles on logic Edmund Husserl is often categorized, alongside figures such as Gottlob Frege, as a Platonist regarding his Metaphysics of Logic. While this might be true for his earlier works, such as the Logical Investigations, it is questionable that this holds true throughout his career. This is especially true for Husserl’s very late work and his shift towards a Genetic Phenomenology. The goal of this presentation is, therefore, to articulate the late Husserl’s conception of what logic fundamentally is. In order to understand Husserl’s position, I want to start with Frege. His paper The Thought will grant us insight into the problem of the Metaphysics of Logic, namely its objectivity. We will see that Frege’s solution to this problem rests on the assumption of a Dualism of Inner and Outer Perception. It is, however, exactly this kind of Dualism Husserl rejects in his later works. In order to show this, I want to compare Frege’s and Husserl’s conception of the Cartesian Doubt in The Thought and the Cartesian Meditations. Next up, I want to show Husserl’s own solution to the problem of the Metaphysics of Logic. While it might be best to look into Formal and Transcendental Logic and Experience and Judgment in order to formulate Husserl’s position, I will rather focus on the Crisis of the European Sciences. The Crisis gives us a more general view into his later style of thinking and his conception of ideal objects. For Husserl, these aren’t the eternal truths Frege envisioned but rather ideal constructs founded within the pre-scientific Lifeworld. It is, of course, very difficult to categorize Husserl’s Metaphysics of Logic. There are elements of Conventionalism, Constructivism, Structural Realism, and others. How one might categorize Husserl in the end depends a lot on the interpretation of these terms and especially on the term “Realism”. Finally, I want to conclude my talk by briefly touching on how Husserl’s position might be relevant for the current debate on Exceptionalism and Normativity of Logic.