Francisca Silva

It has been a matter of great contention how one might demarcate what counts as part of the logical vocabulary. In this paper I want to combine three key thoughts into a new way of demarcating the logical vocabulary. These are the following: that logic should be topic-neutral; that the topic neutrality of logic is best captured through the subject matter transparency of the logical vocabulary; and that some expressions containing non-logical vocabulary may vary in subject matter across modal space. The end-result will be a characterization of what I am calling “topic theoretic invariantism”: that an expression is part of the logical vocabulary if and only if its world-invariant subject matter is the trivial subject matter.

Starting with considerations on why one would want hyperintensional theories of content, this thesis engages in an exploration of three main strands in contemporary hyperintensional semantics and metaphysics: impossible worlds semantics, subject matter theory and truthmaker semantics. Its central claim is that the best hyperintensional theories for various purposes use important insights from these three ways of doing semantics. Starting with a space of possible worlds and expanding it, as Berto and Jago (2019) do, to a space of ‘open’ impossible worlds, we get too anarchic a space of worlds, however closing it under any logical consequence relation, like FDE, we idealize too much if our goal is to model realistic epistemic agents. Adding subject matters (Silva, 2024a) helps to find a happy middle ground. This leaves open the question of how to characterize subject matters, and here the notion of exact verification, I argue, helps in defining a new notion of what we may call `topical truthmaking' which in turn helps define the notion of a subject matter. Closing the circle, recently Berto and Jago (2023) have argued that truthmaker semantics and impossible worlds semantics are notational variants of one another, save for the former’s emphasis on exact verification. I myself argue for this equivalence (Silva, 2024c) by showing that the ontology presupposed by standard truthmaker semantics, as presented in (Fine, 2017a), is the same as the one employed by Berto and Jago (2019). Having developed the aforementioned theoretical background in the first part of the thesis, I then apply the hyperintensional framework in the second part. Namely, I do so to: epistemic logic; the demarcation of the logical vocabulary; and transfeminist philosophy. Longer proofs were saved for a formal appendix.

We seem to have a good grasp of how the subject matters of truth-functional composites depends on their components: it's simply fusion (Hawke, 2018; Fine, 2020; Plebani and Spolaore, 2021 and 2023; Berto 2022). But what relation should the subject matter of subsentential components bear to the subject matter of the sentences they feature in, and what to say about the quantified sentences of first-order predicate logic? Given how well we seem to understand sentential subject matter in the context of propositional logic, I propose a reduction of the subject matter of subsentential components and of quantified sentences to the subject matter of quantifier-free sentences. I argue that the view squares with the Fregean intuitions that gave rise to the construction of first-order logic as we know it today, motivating its adequacy as a theory of subject matter for first-order languages. I then show that this first-order aboutness theory has predictive and explanatory power, leading us to accept a modified version of Yablo's (2014) principle of immanent closure, as well as a new conception of arbitrary objects/reference. Finally, I propose some potential developments and restrictions.

In this paper I provide a new way of thinking of questions using an expanded space of FDE-worlds/state space. This allows both for non-exclusive and non-exhaustive answers to questions concerning one's gender identity. Further, and most crucially for the purposes of this paper, it allows for a new, more general definition of question inclusion that allows for the identification of a new form of hermeneutical injustice. This form of injustice, I argue, affects trans people by keeping them in a prolonged state of gender questioning and confusion in which they only grasp the part of the question Am I X gender identity? that corresponds to the question Do I want to be X gender identity?.

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.

We have to gain from recognizing a relation between epistemic agents and the parts of subject matters that play a role in their cognitive lives. I call this relation “grasping”. Namely, I zone in on one notion of having a partial grasp of a subject matter—that of agents grasping part of the subject matter that they are attending to—and characterize it. I propose that giving up the idealization that we fully grasp the subject matters we attend to allows one to more realistically characterize the epistemic life of agents. To show this, I propose an epistemic logic with partial grasp that has in mind considerations from first-order aboutness theory with the aim of avoiding certain forms of logical omniscience, and which provides an alternative to immanent closure (Yablo Aboutness, Princeton University Press, 2014).

Agents know some but not all logical consequences of what they know. Agents seem to be neither logically omniscient nor logically incompetent. Yet finding an intermediate standard of minimal rationality has proven difficult. In this paper, I take suggestions found in the literature (Lewis, 1988; Hawke, Özgün and Berto, 2020; Plebani and Spolaore, 2021) and join the forces of subject matter and impossible worlds approaches to devise a new solution to this quandary. I do so by combining a space of FDE worlds (Berto and Jago, 2019) with a Lewisian (1988) understanding of subject matters as partitions. By doing so, I show how subject matters impose some order in the anarchic space of FDE worlds, while the worlds allow for distinctions between contents which would not otherwise be available. Combining the two approaches, then, brings us closer to the desired closure principles for knowledge of minimally rational agents.