Research Projects

Tolerant Atheism

Islamophiobia, antisemitism, and other forms of discrimination against religious minorities are a stain on society and they’re on the rise. Religious minorities need special protection in law and in social conduct generally. Set against that, some religious claims can have enormous social impact, including religious businesses refusing to serve gay customers, schools being obliged to promote religious viewpoints, women being denied the same status as men, and so on. Atheists typically respond by wanting to grant no special status for religions. How should we reconcile these two features? I approach these questions from an atheist standpoint: theological doctrine is mostly false and so cannot be used to underpin special status or rights for religious minorities. Rather, we have to see religious as social and cultural constructs, as much as they are lived embodiments of theological doctrine. We should also view race as a social and cultural construct. We can then draw meaningful parallels and view Islamophobia and antisemitism as forms of racism. The conclusion I am tentatively working towards is that we should distinguish conceptually between religions qua religions and religions qua oppressed minorities (for those that are). This allows us to see why, in a predominantly Christian country, what counts as acceptable treatment and protection may differ between a Christian and a Muslim. This is a project I hope to begin work on seriously in 2022.


What makes a thing the thing it is, rather than something else? What makes it the kind of thing it is, rather than something else entirely? Anything at all? I think there’s something that makes humans human, numbers numbers, colours colours. It’s hard to say exactly what it is that makes humans human. I’m much more confident that it’s something, rather than nothing at all. I don’t think these questions are idle speculation. They play a central role in our metaphysical theories of the world. Just what are material objects? What are abstract mathematical objects? For me, the best way to pursue these questions is by first developing a theory of the essences or natures of things, which makes them the very things they are. Along with my colleague Steve Barker, I’ve developed a theory of material objects. We call it Essential Bundle Theory. I quite like it: I think it answers a lot of the questions I was asking about the fundamental make-up of the material world. It also helps answer questions abut metaphysical necessity and possibility: the ways things might have been. There’s a consequence of the view I find puzzling: it doesn’t rule out the possibility that each of us could have been someone else. It allows for contingent identity statements, whereby a statement like a = b is true but possibly false, or false but possibly true. That’s a view many find highly puzzling, or even incoherent. Part of this project is to develop the metaphysics and logic of contingent identity statements, so as to demonstrate their coherence. Besides, I quite like the idea that I could have been you. It gives me (extra) reason to consider your wellbeing and generally work at not being a dick to others.


The latter half of the 20th Century witnessed an ‘intensional revolution’: a great collective effort to analyse notions which are absolutely fundamental to our understanding of the world and of ourselves in terms of a single concept. This was the concept of a possible world: a way things could have been. The idea was used to analyse meaning, information, knowledge, belief, causation, essence, supervenience, conditionality, as well as nomological, metaphysical, and logical necessity. Possible worlds found applications in logic, metaphysics, semantics, game theory, information theory, artificial intelligence, and the philosophy of mind and cognition. However, possible worlds analyses have been facing numerous problems. The problems all concern hyperintensionality: the need for distinctions more fine-grained than the possible worlds apparatus can easily represent. One way to address the problems is by introducing impossible worlds, in addition to possible worlds. Impossible worlds are ways things could not have been. In theory, we then get the benefits of the possible worlds approach but without its limitations. My work on impossibility covers a number of different but related topics: THE METAPHYSICS OF IMPOSSIBLE WORLDS EPISTEMIC LOGIC AND LOGICAL OMNISCIENCE MODELLING INFORMATION

Truthmaker Semantics

Truthmaker Semantics is a new philosophical approach to questions about meaning, with applications in logic and philosophy of language. Truthmaker semantics has roots in the situation semantics of Barwise and Perry and, going back further, in the logical atomism of Russell and Wittgenstein. Both deal in worldly entities — situations, facts, or states of affairs — more specific than entire possible worlds. The defining feature of truthmaker semantics is its exact treatment of conjunction, on which conjunction-truthmakers differ from conjunct-truthmakers. The former are fusions of the latter. This feature was noticed by van Fraassen (1969) and built into a metaphysical theory by Rodriguez-Pereyra (2005). Truthmaker semantics proper begins with Kit Fine’s semantics for counterfactuals (2012), intuitionistic logic (2013), and the logic of containment (2016). Fine’s theory of content (2017a,b) provides an analysis of propositions, subject matter, and partial content. Recently, there has been a small explosion of research in truthmaker semantics, applying the framework to relevant logic, modal logic, proof theory, intuitionistic modal logic, probability theory, attitude verbs, presuppositions, and compositional semantics.

Truth and Truthmaking

This project has three components, giving an account of the truthmakers, the truthbearers, and the relationship between them. As part of this research, I developed an account of (non-linguistic) facts, including negative, conjunctive and existential facts. This is based partially on David Armstrong’s account of states of affairs. My book What Truth Is (OUP 2018) sets out what I think about these areas.

Social Metaphysics

Philosophy matters because it consists of thinking about what matters most to us. And right now, social issues are what matter to many people. Gender identity, trans rights, the effects of racism, disability, or cultural history and how we display it publicly: these are all social philosophical issues. At its best, social philosophy contributions to meaningful social change. At its best, it is continuous with gender studies, black studies, and disability studies. But it is also continuous with traditional areas of philosophy: metaphysics, epistemology, and value theory. When we think about race, gender, or disability, we want to know what it is, whether it really exists; how it relates to underlying biological reality; and whether discrimination is a constituent or maybe a consequence of its continued existence. These are abstract questions, but we don’t ask them idly. We investigate them better to understand our shed social world, and to improve it. This means our answers are important: we have to get it right. And, just as importantly, we have to communicate our answers clearly and effectively to those who are best placed to bring about change. That’s why I helped set up the Nottingham Center for Social Philosophy. You can read more about some of our work here.