The aim of this work is to investigate the problem of Logical Omniscience in epistemic logic by means of truthmaker semantics. We will present a semantic framework based on $$\varvec{W}$$ W -models extended with a partial function, which selects the body of knowledge of the agents, namely the set of verifiers of the agent’s total knowledge. The semantic clause for knowledge follows the intuition that an agent knows some information $$\varvec{\phi }$$ ϕ, when the propositional content that $$\varvec{\phi }$$ ϕ (...) is contained in her total knowledge. We will argue that this idea mirrors the philosophical conception of immanent closure by Yablo (2014), giving to our proposal a strong philosophical motivation. We will discuss the philosophical implications of the semantics and we will introduce its axiomatization. (shrink)

Moral error theory has been criticized on formal grounds for lacking a coherent semantics of moral sentences. In this paper, I provide a truthmaker-based semantics of moral sentences that is compatible with moral error theory. The hyperintensional account draws attention to the exact truth- and falsemakers of moral propositions. Error theorists must assume that propositions that have only moral truthmakers have at least one non-moral falsemaker. A central consequence of the discussion is that moral error theory is compatible with a (...) classical logic of moral notions. (shrink)

Some think that logic concerns the “laws of truth”; others that logic concerns the “laws of thought.” This paper presents a way to reconcile both views by building a bridge between truth-maker theory, à la Fine, and normative bilateralism, à la Restall and Ripley. The paper suggests a novel way of understanding consequence in truth-maker theory and shows that this allows us to identify a common structure shared by truth-maker theory and normative bilateralism. We can thus transfer ideas from normative (...) bilateralism to truth-maker theory, such as non-transitive solutions to paradox, and vice versa, such as notions of factual equivalence and containment. (shrink)

We present a series of proof systems for exact entailment (i.e. relevant truthmaker preservation from premises to conclusion) and prove soundness and completeness. Using the proof systems, we observe that exact entailment is not only hyperintensional in the sense of Cresswell but also in the sense recently proposed by Odintsov and Wansing.

I provide counterexamples to Kit Fine's semantics for imperative and deontic modals. In particular, I argue that the semantics fails to provide necessary conditions for conjunctive imperatives.

Kit Fine distinguishes between inexact and exact truthmaking. He argues that the former can be defined from the latter, but not vice versa, and so concludes that truthmaker semanticists should treat the exact variety of truthmaking as primitive. I argue that this gets things backwards. We can define exact truthmaking in terms of inexact truthmaking and we can’t define inexact truthmaking in terms of exact truthmaking. I conclude that it’s inexact truthmaking, rather than exact truthmaking, that truthmaker semanticists should treat (...) as the primitive semantic relation. (shrink)

I am concerned with epistemic closure—the phenomenon in which some knowledge requires other knowledge. In particular, I defend a version of the closure principle in terms of analyticity; if an agent S knows that p is true, then S knows that all analytic parts of p are true as well. After targeting the relevant notion of analyticity, I argue that this principle accommodates intuitive cases and possesses the theoretical resources to avoid the preface paradox. I close by arguing that contextualists (...) who maintain that knowledge attributions are closed within—but not between—linguistic contexts are tacitly committed to this principle’s truth. (shrink)

The Deontic Principle of Closure (DCL) appears initially to be a highly plausible principle. The DCL is commonly assumed in practical ethical reasoning, as when we make certain inferences about what we (morally) ought to do in particular situations. For example, if I am standing beside a burning house with several victims trapped inside and I have an obligation to rescue them, then if it is necessary for me to open the front door in order for me to lead them (...) out, then it seems that I am morally bound in this situation to open the door. Similarly, if it is the case that I ought to keep my Friday morning 8:00 appointment with my student and it is a necessary condition for keeping the appointment that I wake up some time before 8:00, then I ought to wake up before 8:00. In spite of its attractiveness, however, various worries have been raised about the plausibility of this closure principle. In what follows, I shall critically examine DCL and discuss its plausibility in the face of various objections that have been raised against it. I shall argue that a slightly modified version of the principle circumvents the main objections and holds under several of the more or less standard interpretations of the “ought” operator. (shrink)

Developments in truthmaker semantics for the most part stay clear of the metaphysical issue of what sort of entities serve as the truthmakers and falsitymakers for sentences. It is assumed that perhaps facts or states of affairs (Fine, 2017a; Jago, 2020), with these taken sometimes as concrete particulars (Hawke, 2018) could serve for the job, but nonetheless that some such entities would do. In this paper I take a closer look at the issue of what entities could or could not (...) play the role of truthmakers and falsitymakers in standard truthmaker semantics (Fine, 2016, 2017a,b; Fine and Jago, 2019), based on desiderata imposed by metaphysical and semantic considerations. (shrink)

I am concerned with epistemic closure—the phenomenon in which some knowledge requires other knowledge. In particular, I defend a version of the closure principle in terms of analyticity; if an agent S knows that p is true and that q is an analytic part of p, then S knows that q. After targeting the relevant notion of analyticity, I argue that this principle accommodates intuitive cases and possesses the theoretical resources to avoid the preface paradox.

Belief revision theories standardly endorse a principle of intensionality to the effect that ideal doxastic agents do not discriminate between pieces of information that are equivalent within classical logic. I argue that this principle should be rejected. Its failure, on my view, does not require failures of logical omniscience on the part of the agent, but results from a view of the update as _mighty_: as encoding what the agent learns might be the case, as well as what must be. (...) The view is motivated by consideration of a puzzle case, obtained by transposing into the context of belief revision a kind of scenario that Kit Fine has used to argue against intensionalism about counterfactuals. Employing the framework of truthmaker semantics, I go on to develop a novel account of belief revision, based on a conception of the update as mighty, which validates natural hyperintensional counterparts of the usual AGM postulates. (shrink)

In this paper, we apply relating semantics to the widely discussed problem of free choice between permitted actions or situations in normative systems. Leaving aside contexts in which the free choice principle is obviously unacceptable or uncontroversially valid, we concentrate on free choice for explicit permissions. In order to construct a formal representation of explicit permissions, we introduce a special constant, $\texttt {permit}$, which is analogous to the constant $\texttt {violation}$ used in the Andersonian–Kangerian approach to deontic logic with respect (...) to prohibition and obligation. Consequently, we define a permission operator on the basis of the $\texttt {permit}$ constant and a relation of legitimization. The general idea is that $P \varphi $ is true if and only if $\texttt {permit}$ is true, which means that a permission is actually issued and $\varphi $ is legitimized by $\texttt {permit}$. The intuitive notion of legitimization is formally represented by an operator of relating implication: a non-classical implication that is semantically defined by adding a constraint to the classical meaning of implication to the effect that arguments are related by a special relation. The properties of this relation are based on an informal, intuitive meaning of legitimization and determine the properties of the permission operator. We show that the resulting permission operator possesses the free choice property and avoids certain unwanted consequences that follow from alternative approaches. (shrink)