Julian J. Schloeder

According to success semantics, a belief is true just in case all actions based on it are guaranteed to be successful. A compelling objection has it that the truth of a belief can never guarantee success, since there may always be an unknown impediment or a chance accident. I argue that we must distinguish the completion (i.e. its full and proper performance) of an action from its success (i.e. it achieving its goal). The proper formulation of success semantics is then that a belief is true just in case all actions engendered by the belief are successful if completed. I conclude that this qualification can help to construct a tenable version of the pragmatist theory of truth.

This chapter develops a novel solution to the negation version of the Frege–Geach problem by taking up recent insights from the bilateral programme in logic. Bilateralists explain the meaning of negation in terms of a primitive _B-type_ inconsistency involving the attitudes of assent and dissent. Some may demand an explanation of this inconsistency in simpler terms, but here it is argued that bilateralism’s assumptions are no less explanatory than those of _A-type_ semantics that only require a single primitive attitude, but must stipulate inconsistency elsewhere. A version of B-type expressivism called _inferential expressivism_—a novel semantic framework that characterizes meanings by inferential roles that define which _attitudes_ one can _infer_ from the use of terms—is developed. This framework is applied to normative vocabulary, thereby solving the Frege–Geach problem generally and comprehensively. The chapter includes a semantics for epistemic modals, thereby also explaining normative terms under epistemic modals.

According to the causal theory of reference, the references of (some) natural kind terms are fixed in baptisms. To wit, a so-baptized kind term refers to those things that share a certain inner constitution with the sample used in the baptism. I argue that this is incompatible with the claim that natural kind terms are _open textured_, i.e. that semantics can underdetermine reference. The two views, fixed reference and open textured reference, entail competing claims about the course of science. By examining an episode from the history of science, the discovery of isotopes, I conclude in favor of open texture for natural kind terms.

Certain combinations of sounds or signs on paper are meaningful. What makes it the case that, unlike most combinations of sounds answers to these questions are based on the idea that words stand for something, but it is difficult to say what words such as good, if, or probable stand for. This book advances novel answers based on the idea that words get their meaning from the way they are used to express states of mind and what follows from them. It articulates a precise version of this idea, at a time when the shortcomings of the traditional answers are hotly discussed.

We discuss the nature of retraction, what its felicity conditions and effects on a conversation are, how it compares to other speech acts, and how it relates to social power dynamics. On our account, retractions are proposals to update the context a particular way and, as such, can be rejected. Our formal account models the effect of a retraction on the context to restore the common ground to a prior state, computable from the conversational record. Our account also explains the status of speech acts that follow the target of retraction. Retractions are cognitively costly on our account, but, we argue, this is the right result.

Familiar semantics for terms like ‘because’ appeal to cause or ground, but according to expressivists moral claims cannot enter into such relations. This calls into question whether expressivists can account for moral explanation. I argue that moral expressivists should also be expressivists about explanation. That is, claims like ‘A because B’ are used to express an attitude, namely that one endorses inferring A from B to be suitable for coming to believe A. This allows expressivists to give due to the asymmetric explanatory commitments of different ethical views. Moreover, the account identifies and explains the nature of moral argumentative discourse as proceeding by identifying similarities and adducing distinctions.

Incurvati and Schlöder (_Journal of Philosophical Logic, 51_(6), 1549–1582, 2022) have recently proposed to define supervaluationist logic in a multilateral framework, and claimed that this defuses well-known objections concerning supervaluationism’s apparent departures from classical logic. However, we note that the unconventional multilateral syntax prevents a straightforward comparison of inference rules of different levels, across multi- and unilateral languages. This leaves it unclear how the supervaluationist multilateral logics actually relate to classical logic, and raises questions about Incurvati and Schlöder’s response to the objections. We overcome the obstacle, by developing a general method for comparisons of strength between multi- and unilateral logics. We apply it to establish precisely on which inferential levels the supervaluationist multilateral logics defined by Incurvati and Schlöder are classical. Furthermore, we prove general limits on how classical a multilateral logic can be while remaining supervaluationistically acceptable. Multilateral supervaluationism leads to sentential logic being classical on the levels of theorems and regular inferences, but necessarily strictly weaker on meta- and higher-levels, while in a first-order language with identity, even some classical theorems and inferences must be forfeited. Moreover, the results allow us to fill in the gaps of Incurvati and Schlöder’s strategy for defusing the relevant objections.

Inferential expressivism makes a systematic distinction between inferences that are valid qua preserving commitment and inferences that are valid qua preserving evidence. I argue that the characteristic inferences licensed by the principle of comprehension, from "x is P" to "x is in the extension of P" and vice versa, fail to preserve evidence, but do preserve commitment. Taking this observation into account allows one to phrase inference rules for unrestricted comprehension without running into Russell’s paradox. In the resulting logic, one can derive full second-order arithmetic. Thus, it is possible to derive classical arithmetic in a consistent logic with unrestricted comprehension.

Predicates like _knowable_, _believable_ or _evincible_ each are associated with Fitch-like paradoxes. Given some plausible assumptions, the _prima facie_ reasonable hypotheses that _what is true is knowable/believable/evincible_ entail, respectively, the decidedly unreasonable conclusions that _what is true is known/believed/evinced_. I argue that all Fitch-like paradoxes admit of a common diagnosis and give a uniform semantics for predicates like _knowable_ that avoids the paradoxes while accounting for the intuitive meaning of these predicates. Moreover, I argue that a semantics of the same shape is to be given to similar predicates like _erasable_ or _legible_, whose simple analyses likewise face broadly Fitch-like problems. This semantics also highlights and explains the context-sensitive nature of such predicates.

Deflationists about truth hold that the function of the truth predicate is to enable us to make certain assertions we could not otherwise make. Pragmatists claim that the utility of negation lies in its role in registering incompatibility. The pragmatist insight about negation has been successfully incorporated into bilateral theories of content, which take the meaning of negation to be inferentially explained in terms of the speech act of rejection. We implement the deflationist insight in a bilateral theory by taking the meaning of the truth predicate to be explained by its inferential relation to assertion. We combine this account of the meaning of the truth predicate with a new diagnosis of the liar paradox: its derivation requires the truth rules to preserve evidence, but these rules only preserve commitment. The result is a novel inferential deflationist theory of truth, which solves the liar paradox in a principled manner. We end by showing that our theory and simple extensions thereof have the resources to axiomatize the internal logic of several supervaluational hierarchies, including Cantini’s. This solves open problems of Halbach (2011) and Horsten (2011).

Ian Rumfitt (2000) developed a bilateralist account of logic in which the meaning of the connectives is given by conditions on asserted and rejected sentences. An additional set of inference rules, the coordination principles, determines the interaction of assertion and rejection. Fernando Ferreira (2008) found this account defective, as Rumfitt must state the coordination principles for arbitrary complex sentences. Rumfitt (2008) has a reply, but we argue that the problem runs deeper than he acknowledges and is in fact related to the challenge of establishing proof-theoretic harmony. We motivate a distinctively bilateral criterion for harmony and show how the bilateralist can meet it. This also resolves Ferreira's complaint.

Deflationists about truth hold that the function of the truth predicate is to enable us to make certain assertions we could not otherwise make. Pragmatists claim that the utility of negation lies in its role in registering incompatibility. The pragmatist insight about negation has been successfully incorporated into bilateral theories of content, which take the meaning of negation to be inferentially explained in terms of the speech act of rejection. We implement the deflationist insight in a bilateral theory by taking the meaning of the truth predicate to be explained by its inferential relation to assertion. We combine this account of the meaning of the truth predicate with a new diagnosis of the Liar Paradox: its derivation requires the truth rules to preserve evidence, but these rules only preserve commitment. The result is a novel inferential deflationist theory of truth, which solves the Liar Paradox in a principled manner. We end by showing that our theory and simple extensions thereof have the resources to axiomatize the internal logic of several supervaluational hierarchies, including Cantini’s. This solves open problems of Halbach (2011) and Horsten (2011).

Stephen Read presented harmonious inference rules for identity in classical predicate logic. I demonstrate here how this approach can be generalised to a setting where predicate logic has been extended with epistemic modals. In such a setting, identity has two uses. A rigid one, where the identity of two referents is preserved under epistemic possibility, and a non-rigid one where two identical referents may differ under epistemic modality. I give rules for both uses. Formally, I extend Quantified Epistemic Multilateral Logic with two identity signs. I argue that a uniform meaning for identity tout court can be given by adopting Maria Aloni’s account of reference using conceptual covers. We obtain a harmonious set of rules for identity that is sound and complete for Aloni’s model theory.

Recent advances in the Super Linguistics of pictures have laid the Super Semantic foundation for modelling the phenomena of narrative sequencing and co-reference in pictorial and mixed linguistic-pictorial discourses. We take up the question of how one arrives at the pragmatic interpretations of such discourses. In particular, we offer an analysis of: (i) the discourse composition problem: how to represent the joint meaning of a multi-picture discourse, (ii) observed differences in narrative sequencing in prima facie equivalent linguistic vs pictorial discourses, and (iii) the phenomenon of co-referencing across pictures. We extend Segmented Discourse Representation Theory to spell out a formal Super Pragmatics that applies to linguistic, pictorial and mixed discourses, while respecting the particular ‘genius’ of either medium and computing their distinctive pragmatic interpretations.

In Unreliability and Point of View in Filmic Narration, Emar Maier makes a distinction between reliable and unreliable narrators. The latter, Maier claims, must be a first-person narrator, as an impersonal, third-person narrator lacks an individual perspective that can be unreliable (with some exceptions he sets aside). He concludes that most film adaptations of unreliably narrated novels are not themselves unreliably narrated, for they feature third person perspectives (not through the novel’s narrator’s eyes). I take Maier’s major claims to be (1) that there is a strict distinction between reliable and unreliable narration; and (2) that film shots displaying both a character and that character's hallucinations are not unreliable narration. I will challenge both.

Minimalism about truth is one of the main contenders for our best theory of truth, but minimalists face the charge of being unable to properly state their theory. Donald Davidson incisively pointed out that minimalists must generalize over occurrences of the same expression placed in two different contexts, which is futile. In order to meet the challenge, Paul Horwich argues that one can nevertheless characterize the axioms of the minimalist theory. Sten Lindström and Tim Button have independently argued that Horwich’s attempt to formulate minimalism remains unsuccessful. We show how to properly state Horwich’s axioms by appealing to propositional functions that are given by definite descriptions. Both Lindström and Button discuss proposals similar to ours and conclude that they are unsuccessful. Our new suggestion avoids these objections.

Data involving epistemic modals suggest that some classically valid argument forms, such as _reductio_, are invalid in natural language reasoning as they lead to modal collapses. We adduce further data showing that the classical argument forms governing the existential quantifier are similarly defective, as they lead to a _de re–de dicto_ collapse. We observe a similar problem for disjunction. But if the classical argument forms for negation, disjunction and existential quantification are invalid, what are the correct forms that govern the use of these items? Our diagnosis is that epistemic modals interfere with hypothetical reasoning. We present a modal first-order logic and model theory that characterizes hypothetical reasoning with epistemic modals in a principled manner. One upshot is a sound and complete natural deduction system for reasoning with epistemic modals in first-order logic.

Minimalism about truth is one of the main contenders for our best theory of truth, but minimalists face the charge of being unable to properly state their theory. Donald Davidson incisively pointed out that minimalists must generalize over occurrences of the same expression placed in two different contexts, which is futile. In order to meet the challenge, Paul Horwich argues that one can nevertheless characterize the axioms of the minimalist theory. Sten Lindström and Tim Button have independently argued that Horwich’s attempt to formulate minimalism remains unsuccessful. We show how to properly state Horwich’s axioms by appealing to propositional functions that are given by definite descriptions. Both Lindström and Button discuss proposals similar to ours and conclude that they are unsuccessful. Our new suggestion avoids these objections.

Many classically valid meta-inferences fail in a standard supervaluationist framework. This allegedly prevents supervaluationism from offering an account of good deductive reasoning. We provide a proof system for supervaluationist logic which includes supervaluationistically acceptable versions of the classical meta-inferences. The proof system emerges naturally by thinking of truth as licensing assertion, falsity as licensing negative assertion and lack of truth-value as licensing rejection and weak assertion. Moreover, the proof system respects well-known criteria for the admissibility of inference rules. Thus, supervaluationists can provide an account of good deductive reasoning. Our proof system moreover brings to light how one can revise the standard supervaluationist framework to make room for higher-order vagueness. We prove that the resulting logic is sound and complete with respect to the consequence relation that preserves truth in a model of the non-normal modal logic _NT_. Finally, we extend our approach to a first-order setting and show that supervaluationism can treat vagueness in the same way at every order. The failure of conditional proof and other meta-inferences is a crucial ingredient in this treatment and hence should be embraced, not lamented.

I argue that rejection is a speech act that cannot be reduced to assertion. Adapting an argument by Huw Price, I conclude that rejection is best conceived of as the speech act that is used to register that some other speech act is (or would be) violating a rule of the conversation game. This can be naturally understood as registering *norm violations* where speech acts are characterised by their essential norms. However, I argue that rejection itself is not to be characterised by a norm. Instead, registering violations is a necessary condition for understanding the normative framework in the first place. The core observation is that the concept of an 'illegal move' is intelligible, so a speech act can be (say) an assertion, despite violating the essential norm of asserting. Rejection has the function of pointing out that a move is illegal. But registering rule violations is a precondition of playing games with rules (it is part of the concept 'game'), not itself a rule in a game. A similar special role of rejection (that it is not explicable in the terms provided by a framework, but needed to conceptualise these terms) likely occurs in other frameworks as well, e.g. characterising speech acts by commitments or their effect on a common ground.

We present epistemic multilateral logic, a general logical framework for reasoning involving epistemic modality. Standard bilateral systems use propositional formulae marked with signs for assertion and rejection. Epistemic multilateral logic extends standard bilateral systems with a sign for the speech act of weak assertion (Incurvati and Schlöder 2019) and an operator for epistemic modality. We prove that epistemic multilateral logic is sound and complete with respect to the modal logic S5 modulo an appropriate translation. The logical framework developed provides the basis for a novel, proof-theoretic approach to the study of epistemic modality. To demonstrate the fruitfulness of the approach, we show how the framework allows us to reconcile classical logic with the contradictoriness of so-called Yalcin sentences and to distinguish between various inference patterns on the basis of the epistemic properties they preserve.

This paper presents a novel account of focal stress and pitch contour in English dialogue. We argue that one should analyse and treat focus and pitch contour jointly, since (i) some pragmatic interpretations vary with contour (e.g., whether an utterance accepts or rejects; or whether it implicates a positive or negative answer); and (ii) there are utterances with identical prosodic focus that in the same context are infelicitous with one contour, but felicitous with another. We offer an account of two distinct pitch contours that predicts the correct felicity judgements and implicatures, outclassing other models in empirical coverage or formality. Prosodic focus triggers a presupposition, where what is presupposed and how the presupposition is resolved depends on prosodic contour. If resolving the presupposition entails the proffered content, then the proffered content is uninteresting and hence the utterance is in-felicitous. Otherwise, resolving the presupposition may lead to an implicature. We regiment this account in SDRT.

We develop a novel solution to the negation version of the Frege-Geach problem by taking up recent insights from the bilateral programme in logic. Bilateralists derive the meaning of negation from a primitive *B-type* inconsistency involving the attitudes of assent and dissent. Some may demand an explanation of this inconsistency in simpler terms, but we argue that bilateralism’s assumptions are no less explanatory than those of *A-type* semantics that only require a single primitive attitude, but must stipulate inconsistency elsewhere. Based on these insights, we develop a version of B-type expressivism called *inferential expressivism*. This is a novel semantic framework that characterises meanings by inferential roles that define which *attitudes* one can *infer* from the use of terms. We apply this framework to normative vocabulary, thereby solving the Frege-Geach problem generally and comprehensively. Our account moreover includes a semantics for epistemic modals, thereby also explaining normative terms under epistemic modals.

We present an inferentialist account of the epistemic modal operator might. Our starting point is the bilateralist programme. A bilateralist explains the operator not in terms of the speech act of rejection ; we explain the operator might in terms of weak assertion, a speech act whose existence we argue for on the basis of linguistic evidence. We show that our account of might provides a solution to certain well-known puzzles about the semantics of modal vocabulary whilst retaining classical logic. This demonstrates that an inferentialist approach to meaning can be successfully extended beyond the core logical constants.

Anti-realism is plagued by Fitch’s paradox: the remarkable result that if one accepts that all truths are knowable, minimal assumptions about the nature of knowledge entail that every truth is known. Dorothy Edgington suggests to address this problem by understanding p is knowable to be a counterfactual claim, but her proposal must contend with a forceful objection by Timothy Williamson. I revisit Edgington’s basic idea and find that Williamson’s objection is obviated by a refined understanding of counterfactual knowability that is grounded in possible courses of inquiry. I arrive at a precise definition of knowability that is not just a technical avoidance of paradox, but is metaphysically sound and does justice to the anti-realist idea.

The knowledge norm of assertion is the subject of a lively debate on when someone is in a position to assert something. However, not much has been said about the logic that underlies such debate. In this paper, I propose a formalisation of the knowledge norm in a deontic logic that aims to be explanatory and conceptually sound. Afterwards, I investigate some problems that this formalisation makes visible. This reveals some significant limitations of the underlying logic: it can neither contain Axiom 4 nor Axiom C4. Moreover, sentences of the form p and I have not asserted that p appear to licence a violation of deontic rules.