Research

Meaningless Communication
Towards an Understanding-First Approach
Forthcoming in The Journal of Philosophy.

In this paper I explore how we can conceive of communication without recourse to the notion of meaning. I argue that we should think about understanding as a kind of skill or knowledge-how with both a practical and cognitive component. Further, one expression can be understood in different ways with respect to different communicational functions it can fulfil. With the notion of understanding of expressions – competence – in hand, I explain how it relates to the understanding of utterances – comprehension. Finally, I give an account of communication and discuss the advantages which come from adopting this perspective.

The Nietzschean Sellars
Remarks on the Nietzsche-Sellars view of Mind
Co-authored with Elsa Magnell.
Forthcoming in The Southern Journal of Philosophy
Link to pdf.

We discuss the striking similarities between Friedrich Nietzsche’s and Wilfrid Sellars’ respective philosophies of mind. Drawing especially on recent Nietzsche scholarship of consciousness is essentially the same as Sellars’ view of conceptually structured thought. In particular, we argue that both consider structured thinking to be a linguistic phenomenon whose structure, in turn, arises contingently from social interactions within a community. Further, both views provide for a special role to be played by specifically mentalistic vocabulary in making it possible to engage with the mental states of others in a reflective way.

From Epistemic Norms to Logical Rules
Epistemic Models for Logical Expressivists
Journal of Philosophical Logic, Vol. 52, No. 6, pp. 1517-1533.
Link to pdf.

I construct a system of semantics for classical and intuitionistic propositional logic based on epistemic norms governing belief expansion. Building on the AGM-framework of belief change, I give a generalisation of Gärdenfors’ notion of belief systems which can be defined without reference to a logical consequence operator by using a version of the Ramsey Test. These belief expansion systems can then be used to define epistemic models which are sound and complete for either classical or intuitionistic propositional logic depending on which of the two notions of epistemic validity, identied by Levi and Arló-Costa, is used. Finally, I offer a discussion on how these results can be understood as providing a model theory within the framework of logical expressivism.

A Fixed-Point Problem for Theories of Meaning
Synthese, Vol. 200, No. 24, pp. 1-15.
Link to pdf.

I argue that it’s impossible for there to be a single universal theory of meaning for a language. First, I argue for some minimal requirements on expressiveness that a language must meet to be able to express in order to have a single unified theory of meaning. It has been well-known since Tarski that theories of meaning whose central notion is truth can’t be expressed in a language which they apply to. Here, I develop Quine’s formulation of the Liar Paradox in grammatical terms and use this to extend Tarski’s result to all theories of meaning. This general version of the paradox can be formalised as a special case of the Lawvere Fixed-Point Theorem applied to a categorial grammar. Taken together with the initial arguments, I infer that a universal theory of meaning is impossible and conclude the paper with a brief discussion on what alternatives are available.

Knowledge as a Responsibility Concept
E-mail for draft.

In this paper I argue that the concept of knowledge is best understood in terms of trust and responsibility. As a motivation for the approach, I provide a revision of Craig’s genealogy, arguing that knowledge is supposed to track informants who are responsible providers of testimony. Then, I provide a social re-interpretation of the Belief-Doubt model, advanced by Levi and Peirce, as the basic structure of epistemic interactions and give a basic taxonomy of testimony in terms of what responsibilities that the testimonial act take on. Then, I argue that judgements about whether someone knows P are best understood as evaluations of whether we would trust them with respect to a knowing act of testimony. Finally, I offer a discussion on how the account can still make room for the specifically epistemic value of knowledge.

Knowing Who and Knowing How
Two Ways to Understand Reference
E-mail for draft.

Here, I’m concerned with the question of what it takes to understand what a singular term refers to. In recent years there has been a lively debate about whether referring requires that the speaker or hearer has a cognitive fix on the object of reference. I will argue that both sides of this discussion are largely right but are talking about two distinct practices of using terms to refer; uses which fulfil what I call the talking-about and picking-out functions of singular terms. Then, to understand an utterance of a singular terms we will need different information depending on which function the term was used to fulfil. In the talking-about case, I argue that a version of the standard analysis of knowledge-who is sucient. But to understand singular terms uttered to fulfill a picking-out function, we need knowledge-who in the sense of knowing how to find what’s referred to sufficiently well to perform a contextually specied action.

Some Necessary Revisions
Modality and Belief Revision
E-mail for draft.

In this paper I discuss the normativist approach to modality, advanced by Thomasson. I argue that for modal claims to fulfil the interpersonal function of enabling the negotiation of norms, which normativists take to be central, they must also fulfil an information conveying function. I then propose that the information conveyed by alethic modals is structured by the results of simulated belief revision. Taking this approach allows us to both explain modal logic and the hierarchy of different strength which holds for alethic modals whilst still agreeing with the modal normativist that modal claims are not descriptions of states-of-affairs.

From Belief Change to Modality
Epistemic Semantics for Modal and Conditional Logic
E-mail for draft.

This paper sets out to extend the epistemic semantics presented by in another paper to modal and conditional logics. To do so, it extends the notion of belief expansion systems, inspired by the AGM-model of belief change, to include belief revision, and uses them as models for both conditional and modal logic. In the first case, this applies the well-known approach to conditionals began by Gärdenfors, in a weaker setting which doesn’t assume an underlying logic. As such, it results in semantics for both classical conditional logic as well as the intuitionistic conditionals studied by Weiss. For modal logics, it uses the condition that □φ is accepted if and only if φ is accepted under every belief revision. As a result of this system of semantics, we get soundness and completeness theorems for both intuitionistic and classical systems of modal and conditional logic on the basis of a single type of structure.

On Epistemic Semantics and Kripke Models
E-mail for draft.

In this paper, I compare the normativist epistemic semantics I’ve advanced elsewhere with standard Kripke models for intuitionistic logic. To do so, I prove a categorial equivalence between a subcategory of belief expansion systems with appropriate morphisms between them and a subcategory of Kripke models and p-morphisms. I then offer a brief discussion on how to interpret the restrictions required for the equivalence as revealing the different advantages and disadvantages of the respective systems.