My overall research profile can be characterized along six themes:

Theme 1. Much of my recent research energy has gone into work on artificial intelligence and machine learning in particular. I have had expertise in computer science for decades at this point, having written the data compression algorithm used by the spacecraft in NASA’s Mars Observer Mission in 1991. For the past few years I have developed coding skills and am investigating the potential to use machine learning algorithms as part of philosophical methodology (e.g., by creating an artificial philosopher). I am most interested in reinforcement learning algorithms (e.g., partially observable markov decision processes), unsupervised algorithms, and Bayesian networks as they have been utilized in projects like Bayesian Theory of Mind (BToM). I am currently finishing a book on philosophy and machine learning, which brings many of these themes together and emphasizes the role of explainable artificial intelligence (XAI) in philosophical applications of these algorithms. I have recently published a paper, “The End of Vagueness: Technological Epistemicism, Surveillance Capitalism, and Explainable Artificial Intelligence,” (with Alison Duncan Kerr), Minds and Machines 2022, in which we argue that machine learning algorithms are already decreasing vagueness in human languages. Moreover, because of my groundbreaking work on reasons in metaethics, I write about explainable AI in light of the fundamental kinds of reasons humans utilize. Finally, I have worked on the Ethics of Socially Disruptive Technology (ESDIT) project at the University of Twente, which involves writing about a huge range of topics in applied ethics related to artificial intelligence and other technologies. I contributed to the forthcoming EDSiT book and have several works in progress on applied ethics of technology.

Theme 2. The philosophical discussion about reasons in metaethics and how they are linked to rationality, morality, explanation, deliberation, and much else is one of the defining characteristics of analytic philosophy (the dominant version of Western philosophy in the English-speaking world). The Semantics for Reasons book (coauthored with Bryan Weaver in 2019) aims to fundamentally change debates in metaethics by exposing major common assumptions that are mistaken and pointing the way toward new significant issues for study. Moreover, it has a sequel, Reasons in the Normative Realm, which is now under contract at Oxford, and ready for submission in the next couple of months. It focuses on presenting and defending a reasons first approach in metaethics, which is the view that all normative phenomena can be explained in terms of reasons. We use ‘normative’ in a broad way to include phenomena like ‘reason’, ‘ought’, ‘fitting’, ‘obligated’, ‘must’, ‘permitted’, ‘may’, ‘because’, ‘might’, as well as ‘good’, ‘bad’, ‘right’, and ‘wrong’.

Theme 3. My work has played a large role in popularizing the term ‘conceptual engineering’ and the methodology it names. The idea behind conceptual engineering is that instead of just analysing our concepts, philosophers should be assessing their worth and replacing those that are defective. This idea has turned into a movement that continues to grow and expand across the contemporary philosophical scene. See my “Philosophy as the Study of Defective Concepts,” for an overview. I am currently editing a three-volume collection on conceptual engineering with Springer Press (with Manuel Gustavo Isaac and Steffen Koch as co-editors) and working on a book on conceptual engineering called Replacing Philosophy along with a number of papers on this topic.

Theme 4. I am internationally renowned for my work on truth and the liar paradox. My book, Replacing Truth, appeared in 2013 with Oxford University Press, and a book symposium on it was recently published. In addition, I have published nine additional papers on truth, including the central one in Philosophical Review, since 2007, with the most recent in 2021 (“Conceptual Engineering for Truth”— https://link.springer.com/article/10.1007/s11229-019-02491-4).

Theme 5. I also work on philosophy of science, most significantly on measurement theory and scientific change. Measurement theory is the study of how mathematics applies to the natural world in science. In a paper, “On the Indeterminacy of the Meter,” (Synthese, 2017) I use measurement theory to show that if there is a minimal length (e.g., Planck length), then there is only about a 1 in 21 million chance that ‘meter’ is determinate. Measurement theory plays a crucial role in my theory of metrological naturalism (introduced in Replacing Truth), which is a general philosophical methodology; I suggest that a philosophical theory of some concept X ought to be cast as a measurement system for X. Measurement systems are the basis for the scientific study of measurement, as in measurement theory and metrology. A recent paper, “Philosophy as the Study of Defective Concepts,” explores this theme.

Theme 6. I have written on the history of analytic philosophy, focusing on figures like Wilfrid Sellars, Rudolph Carnap, and Donald Davidson. I edited a collection of Wilfrid Sellars’ papers called In the Space of Reasons with Robert Brandom, which was published by Harvard University Press in 2007. I also published a paper, “Wilfrid Sellars’ Anti-Descriptivism” on Sellars, and his idea of the space of reasons figures prominently in my book Reasons in the Normative Realm (with Bryan Weaver), which is under contract with Oxford University Press (see above). I also recently published “Pragmatism without Idealism,” (with Robert Kraut) which identifies key insights from classical pragmatists like William James and distinguishes them from mistakes or less plausible views that are often confused with the insights. Finally, much of my work on conceptual engineering (see above) is inspired by Rudolph Carnap’s method of explication. My book (in preparation), Replacing Philosophy, explores this idea in detail. I have also published on other areas in the history of philosophy, like “Locke on Reflection”, and this expertise finds its way into my teaching (e.g., the course on Russell’s History of Western Philosophy).