I am Professor of Philosophy at the University of Arizona, where I have taught since 2004. My prior teaching experience includes positions at the University of Memphis (1990-2003) and Illinois State University (1982-1989). My primary research and publication areas are metaethics and Kant’s ethics. Beyond my research, I have also been actively involved in editing.
Upon my retirement at the end of the Spring 2025 semester, I intend to remain active in the profession, particularly in working with graduate students.
Research Interests (in no particular order)
Kant’s Ethics
Some of my articles on Kant’s ethics are included in Significance and System: Essays on Kant’s Ethics (Oxford UP, 2017).
I am the author of a book-length guide to Kant’s Doctrine of Virtue (Oxford UP, 2021).
I am now writing a book, Kant on Moral Evil for the Cambridge Elements series on Kant’s philosophy.
Sorin Baiasu and I are editors of two collections of newly written essays on Kant’s moral and political philosophy, Kant on Practical Justification (Oxford UP, 2013) and Kantian Citizenship (Routledge, 2025). We co-edited The Kantian Mind (Routledge, 2024) which contains 45 newly written essays by renowned scholars covering a vast range of topics from the entire Kantian corpus.
Metaethics & Moral Phenomenology
In addition to my ongoing work on Kant’s ethics, I continue to collaborate with Terry Horgan. We have co-authored 34 articles and book chapters, among them 7 articles feature the well-known Moral Twin Earth argument against forms of ethical naturalism. Another collection of our articles defends what we call “cognitivist expressivism.”
Terry and I were recipients of a John Templeton Foundation Grant in support of a book in progress, Illuminating Reasons: An Essay in Moral Phenomenology. This grant also supported a conference held in 2014, featuring eight talks by prominent figures. Some of our published articles are on topics in moral phenomenology that will become book chapters.
Moral Epistemology
Aaron Zimmerman, Karen Jones, and I co-edited The Routledge Handbook of Moral Epistemology featuring 30+ commissioned essays covering topics relating moral epistemology to science, normativity, and its applications.
Workshop in Normative Ethics & Oxford Studies in Normative Ethics
I began the annual Arizona Workshop in Normative Ethics (WiNE) in 2010 which takes place in Tucson each January. I am the editor of the annual Oxford Studies in Normative Ethics each volume of which features a selection papers presented at the previous Workshop. Volumes 1-15 are in print.
The 17th Workshop, January 15-17, 2026 will feature Julia Markovits and Mark Schroeder as keynote speakers. The full program will be available mid-July and will be posted on the workshop website which includes details about the workshop location, accommodations, and registration (which is free). Beginning with this Workshop David Clark and I will be organizing the workshops and editing the associated Oxford Studies volumes.
Selected Publications
“The Good, the Bad, and the Badass: Reflections on the Descriptive Adequacy of Kant’s Conception of Moral Evil,” in Significance and System: Essays on Kant’s Ethics, New York: Oxford University Press (2017).
“Doctrine of Virtue,” In S. Baiasu and M. Timmons (eds.), The Kantian Mind, Routledge Press, forthcoming.
“The Phenomenology of Kantian Respect for Persons,” with Uriah Kriegel. In R. Dean and O. Sensen (eds.), Respect. Cambridge University Press, forthcoming.
“The Phenomenology of Deliberation and the Non-Naturalistic Fallacy,” with Terry Horgan. In N. Sinclair (ed.), The Naturalistic Fallacy. Cambridge University Press, forthcoming.
“Gripped by Authority,” with Terry Horgan, Canadian Journal of Philosophy, special issue, forthcoming.
“The Phenomenology of Moral Authority,” with Terry Horgan In New Essays on Moral Skepticism, D. Muchaca (ed.). Cambridge University Press (2018): 115-140.
“Sentimentalist Moral-Perceptual Experience and Realist Pretensions: A Phenomenological Inquiry,” with Terry Horgan. In K. Steuber and R. Debes (eds.), Ethical Sentimentalism. Cambridge University Press (2017): 86-106.
“Exploring Intuitions on Moral Twin Earth: A Reply to Sonderholm,” with Terry Horgan. Theoria (2015): 1-21
“Emulation, Love of Honor, and the Devilish Vices,” with Houston Smit. Essays on Kant’s Lectures on Ethics, Lara Denis and Oliver Sensen (eds.). Cambridge: Cambridge University Press (2015): 256-276.
“Modest Quasi-Realism and the Problem of Deep Moral Error,” with Terry Horgan. Essays on the Philosophy of Simon Blackburn, Michael Smith and Robert Johnson (eds.). Oxford University Press, (2015): 190-209.
“Ethical Conservatism and the Psychology of Moral Luck,” with Shaun Nichols and Theresa Lopez. In Empirically Informed Ethics, M. Christen, J. Fischer, J. Huppenbauer, C. Tanner, & C. van Schaik, eds., Springer (2013): 160-17.
“Reflections on the Project, Problems, and Promise of Moral Phenomenology,” In Prolegomenon to Moral Phenomenology, M. Khodadadi, ed. Tehran: Qoqnoos Publications (2013). (Trans. and published in Farsi.
“Kant’s Grounding Project in the Doctrine of Virtue,” with Houston Smit. In Kant on Practical Justification: New Interpretations. M. Timmons and S. Baiasu (eds). Oxford: Oxford University Press (2013): 229-268.
“The Perfect Duty to Oneself as an Animal Being”, in Kant’s Tugendlehre, A. Trampota, O. Sensen, and J. Timmermann (eds.), Berlin and New York: de Gruyter (2013): 2210243.
“A. C. Ewing’s First and Second Thoughts in Metaethics”, with Jonas Olson, in Underivative Duty: British Moral Philosophers from Sidgwick to Ewing, T. Hurka (ed.), Oxford: Oxford University Press (2011): 183-211.
“The Moral Significance of Gratitude in Kant’s Ethics”, with Houston Smit, Southern Journal of Philosophy 49 (2011): 295-325.
“Toward a Sentimentalist Deontology”, In Moral Psychology, vol. 3, Walter-Sinnott-Armstrong (ed.), Oxford University Press, 2008.
“What Can Moral Phenomenology Tell Us about Moral Objectivity?” with Terry Horgan. In Objectivism, Subjectivism, and Relativism in Ethics, E.R. Paul, F.D. Miller, and J. Paul (eds.), Cambridge University Press, 2008.
“Moorean Moral Phenomenology”, with Terry Horgan. In Moorean Themes in Epistemology and Ethics, S. Nuccetelli & G. Seay (eds.), Oxford University Press, 2007.
“Ethical Objectivity, Humanly Speaking: Reflection on Putnam’s Ethics without Ontology“, Contemporary Pragmatism, 2007.
“Cognitivist Expressivism”, with Terry Horgan. In Metaethics after Moore, T. Horgan & M. Timmons (eds.), Oxford University Press, 2006.
“The Categorical Imperative and Universalizability”, in Kant’s Groundwork for the Metaphysics of Morals: New Interpretations, Christoph Horn & Dieter Schonecker (eds.), de Gruyter, 2006.
“Expressivism, Yes! Relativism, No!” , with Terry Horgan. In Oxford Studies in Metaethics, vol. I., R. Shafer-Landau (ed.), Oxford University Press, 2006.
“Moral Phenomenology and Moral Theory”, with Terry Horgan. Philosophical Issues 15, 2005.
mtimmons@arizona.edu | University of Arizona, P.O. Box 21007, Tucson, AZ 85721