Professor Robert Williams


I studied Mathematics and Philosophy as an undergraduate, followed by a BPhil in Philosophy (both at Oxford), then continued in graduate study at the University of St Andrews at the Arche research centre. My PhD research was on the Inscrutability of Reference, under the supervision of Crispin Wright. I moved to Leeds in 2005 and have stayed ever since, as lecturer, reader and then professor of theoretical philosophy. Outside of philosophy, my main interest is running, particularly fell running.





Research interests

Research Interests

  • Metaphysics
  • Formal Epistemology
  • Philosophy of mind and language
  • Philosophy of Logic and Mathematics

Supervision projects.

Things that I'm thinking about right now, and that I'd be delighted to help construct a PhD (or postdoc) application around.

  • Personal identity. Radical interpretation grounds the content of psychological states in terms of an agent's history of experience and action, and so partly in facts about the agent's persistence through time. But psychological theories of personal identity ground facts about persistence through time in facts about the content of psychological states of an agent's temporal stages. Is it tenable to maintain both together? I'm also interested in indeterminacy and personal identity, and the role of personal identity in normative theory.
  • Group representation. We attribute to groups and institutions beliefs and desires---in team planning, in political commentary, and our theories. But are there objective facts about what beliefs and desires groups have, or are is this an anthropomorphic projection? If there are objective facts (or even projected facts) by virtue of what do they obtain? List and Pettit have suggested that we can apply radical interpretation to group agents to answer this question. There's a lot of interesting issues about how exactly to work out that idea, and my work on radical interpretation in the individual case gives me an interest in, and a platform for, working on the metaphysics of group attitudes.
  • Vagueness and Indeterminacy: my recent focus has been on moral indeterminacy (cf. my 2017 Ethics paper), which builds on work on rational decision making under indeterminacy. As well as normative projects, there are also technical ones here, for example, to generalize and prove representation theorems for the nonclassical decision theories I describe in my 2016 paper. 
  • Quantification: I'm interested in how we manage to quantify over absolutely everything, given that all our generalizations can be truly interpreted in a restricted domain (cf. Skolem's paradox). I'm interested in the way that generalizations relate to normative reasons (cf. Kantian universalizability constraints). And I'm interested in the logic of unrestricted quantification (e.g. Dummett's claim that its logic should be intuitionistic, a view that has become prominent again thanks to recent work by Feferman and Rathjen).
  • Metaethics and metasemantics: I'm increasingly interested in normative discourse as a test case for general foundational theories of content (cf moral twin earth and causal/interpretationist theories of content). I'm also thinking about the issues raised and positive theory proposed in Gibbard's 2012 book on the normativity in meaning.

Beyond this I'm willing to supervise in any of my areas of research interest. Please do drop me a line if you want to discuss potential PhD projects, for example in:

  • Conditionals: the logic, semantics and pragmatics of indicative and counterfactual conditionals. Triviality theorems.
  • Indeterminacy and vagueness.
  • Philosophy of mathematics
  • Probability: subjective and objective.
  • Personal identity
  • Logic: classical and non-classical; metaphysics, epistemology and normativity.
  • Ontological commitment: the relation between metaphysics and language.
  • Metasemantics: the foundations of reference and representation.

Selected Publications 

  • 'Normative Reference Magnets' Philosophical Review (2018).
  • 'Indeterminate Oughts', Ethics (2017).
  • 'Representational Scepticism: the bubble puzzle', Philosophical Perspectives (2017).
  • 'Non-classical minds and indeterminate survival', Philosophical Review (2014)
  • 'Decision making under indeterminacy', Philosopher's Imprint (2014)
  • 'A theory of metaphysical indeterminacy' (with EJ Barnes). Oxford Studies in Metaphysics, (2011).
  • 'Fundamental and derivative truths', Mind (2010).
  • 'Eligibility and Inscrutability', Philosophical Review (2007).

Selected Grants

  • with Seamus Bradley as researcher: Imprecise probability models of belief. Marie Curie Individual Fellowship. (2018-2020).
  • with Ed Elliott as researcher: The nature of belief. Marie Curie Individual Fellowship. (2017-19)
  • with Darren Bradley as researcher:  Carnap and the Limits of Metaphysics. Marie Curie Individual Fellowship. (2015-17)
  • The Nature of Representation (2012-17, ERC starting research grant).  
  • with Elizabeth Barnes and Ross Cameron as co-Is: Metaphysical Indeterminacy (2009-13, AHRC major research grant). 
  • The cognitive role of Indeterminacy (2009-11, British Academy Research Development Award).
<h4>Research projects</h4> <p>Any research projects I'm currently working on will be listed below. Our list of all <a href="">research projects</a> allows you to view and search the full list of projects in the faculty.</p>

Student education

In the past I have taught modules such as The Mind, Logic, (level 1); Introduction to Philosophy of Language (level 2); Advanced Philosophy of Logic, Advanced philosophy of Language, Philosophy of Logic and Mathematics, Philosophy of Mind and Knowledge (level 3) and masters courses in the Self, Philosophy of Language, as well as research skills modules.

I currently supervise PhD students and postdoctoral researchers/research projects.

PhD supervision:

  • *Aleksander Domoslawski. 2018-. PhD on semantic plasticity (WROCAH AHRC funding).
  • *Alexander Siantonas. 2018-. PhD on principles of charity in metaphysics.
  • *Miriam Bown. 2017-. PhD on self-referential probability.
  • *Gary Mullen 2014-2018. PhD on options within decision theory. (WROCAH AHRC funding).
  • Fabio Ceravolo 2014--. PhD on mereology in science.
  • Josh Matthews 2014-2018. PhD on vagueness and experimental philosophy. (WROCAH AHRC funding).
  • *Nick Tasker. 2013-2017 PhD on the metaphysics of words. (NatRep funding, Jacobsen fellow 2016-7, currently stipendiary lecturer at Hertford College, Oxford).
  • *Will Gamester 2013-2017 PhD on truth pluralism. (NatRep funding, Jacobsen fellow 2016-7, currently British Academy Postdoctoral Award holder, Leeds.).
  • *Laura Crosilla. 2012-2017 PhD on the philosophy of constructive mathematics. (NatRep part funding, currently teaching fellow at University of Birmingham). 
  • *Thomas Brouwer. PhD 2013. "The metaphysical commitments of logic" (Jacobsen fellow 2012-13. Then postdoc at the Northern Institute of Philosophy. Currently Research Development Assistant, Leeds.)
  • *Mirja Holst. PhD 2012. "Ordering semantics for incomplete descriptions". (2012: DAAD award at the University of Hamburg, then research associate at the University of Hamburg, currently lecturer at the American University of Viet Nam.)
  • *Alex Oldemeier. PhD 2012. "The epistemology of abstraction" (AHRC award 2009-11. Jacobsen fellow 2011-12).
  • Stephan Kraemer. PhD awarded 2011. "Second-Order Quantification and Ontological Commitment".  (This thesis won the Wolfgang-Stegmller-Preis, was lecturer at the university of Glasgow, now researcher at the University of Hamburg)

Lead supervision marked by *.

Postdoctoral researchers

  • Thomas Brouwer (2016-7), currently research development assistant at Leeds 
  • Simon Hewitt (2016-7), currently Leverhulme Trust early career fellow at Leeds
  • Gail Leckie. (2015-7), currently stipediary lecturer at Mansfield college, Oxford.
  • Daniel Elstein. (2015-7), currently lecturer, University of Leeds.
  • Rachel Goodman (2013-15), currently tenure-track at University of Nebraska, Lincoln.
  • Jennifer Carr (2013-15), currently tenure-track at the University of San Diego.

Research Project Supervision

  • Seamus Bradley Imprecise probability models of belief. Marie Curie Individual Fellowship. (2018-2020).
  • Ed Elliott The nature of belief. Marie Curie Individual Fellowship. (2017-19)
  • Darren Bradley Carnap and the Limits of Metaphysics. Marie Curie Individual Fellowship. (2015-17)
  • Paolo Santorio Probability and Modality Marie Curie Career Intergration Fellowship (2013-17).

Research groups and institutes

  • Centre for Ethics and Metaethics
<h4>Postgraduate research opportunities</h4> <p>We welcome enquiries from motivated and qualified applicants from all around the world who are interested in PhD study. Our <a href="">research opportunities</a> allow you to search for projects and scholarships.</p>