Karen Margrethe Nielsen

Fellow & Tutor in Philosophy; Associate Professor in Philosophy

I work on ancient philosophy, with special emphasis on Aristotle’s ethics and moral psychology. My current research is funded by a Leverhulme Major Research Fellowship (2022-24), which enable ‘well-established, distinguished researchers in the humanities and social sciences to complete a major piece of research’. My leave will result in a monograph titled Prohairesis: Aristotle’s Theory of Decision and its Legacy. At the time of award, I was the first philosopher in Oxford to receive the fellowship since John Hyman (2009) and Timothy Williamson (2008), and one of only three recipients (out of thirty) who was not yet a full professor.

I have recently published a book in the Cambridge Elements series titled Vice in Ancient Philosophy: Plato and Aristotle on Moral Ignorance and Corruption of Character (CUP, 2023) and was the editor (with Devin Henry) of Bridging the Gap between Aristotle’s Science and Ethics (CUP, 2015). My articles have appeared in specialist and generalist journals, including Phronêsis, Oxford Studies in Ancient Philosophy, Philosophical Review, Classical Quarterly and Philosophical Perspectives, as well as in edited volumes. My doctoral students include Bradford Kim (Van Leer Institute) and Katharine O’Reilly (Toronto Metropolitan University). My academic career spans four countries and five universities: Oxford, Western University, Canada, Cambridge (very briefly), Cornell, and The Norwegian University of Science and Technology. 

I like to explore first-order philosophical questions in the course of analysing ancient Greek and Roman texts, covering topics ranging from deliberation and its preconditions, compulsion and voluntariness, coincidence and necessity, developmental biology, virtue and vice. In the more distant future, I hope to explore ancient theories of compelled and coerced action in a project I have dubbed ‘Between the Devil and the Deep Blue Sea: Coercion and Compulsion in Ancient Greek Thought’. I am also thinking about voluntaria mors in antiquity. But unless Oxford increases academic pay and reduces our workloads, you may instead find me working 8-3:30 as a mid-level bureaucrat somewhere in Norway, much like the last soul to choose a life in Plato’s Republic.

Career & Education

  • 2022-24: Leverhulme Major Research Fellowship, for the project Prohairesis: Aristotle’s Theory of Decision and its Legacy
  • 2013 – present: Associate Professor, Faculty of Philosophy and Tutorial Fellow, Somerville College, University of Oxford. Member of the Faculty of Classics 2022-
  • 2012: Visiting Scholar by Election, Corpus Christi College, University of Oxford, Michaelmas
  • 2012-13: Member of the Center for the Study of Greek and Roman Antiquity, Corpus Christi College
  • 2005-12: Associate and Assistant Professor (TT), Department of Philosophy, Western University, Canada
  • PhD, Sage School of Philosophy, Cornell University (2006); Fulbright Fellowship 2000-1. M.A. and B.A., Department of Philosophy, Norwegian University of Science and Technology


Recent graduate seminars

  • Aristotle’s Defence of Natural Slavery and its Legacy (TT 2022)
  • Vice in Ancient Philosophy (HT 2020)
  • Aristotle on Intellect and Virtue, with Dhananjay Jagannathan (Columbia) and Terry Irwin (TT 2019)
  • Aristotle’s Three Ethics, with Terry Irwin (HT 2014)
  • Latin Philosophy (TT 2014)


  • Aristotle’s Nicomachean Ethics, Latin Philosophy


  • Aristotle’s Nicomachean Ethics (Greek and translation)
  • Plato’s Republic (Greek and translation) 
  • Latin Philosophy: Cicero and Seneca (Latin and Translation)
  • Aristotle on Nature, Life, and Mind (Greek and Translation)
  • Plato on Knowledge, Language and Reality in Theaetetus and Sophist (Greek and Translation)
  • Ethics
  • Moral Philosophy 
  • General Philosophy
  • Early Modern Philosophy 
  • Plato’s Meno & Euthyphro (Greek and translation) 
  • Early Greek Philosophy (Greek) 



1. Vice in Ancient Philosophy: Plato and Aristotle on Moral Ignorance and Corruption of Character, Cambridge Element (Cambridge University Press, 2023)

2. Bridging the Gap Between Aristotle’s Science and Ethics, D. Henry and K. M. Nielsen (eds.) (Cambridge University Press, 2015)


3. Prohairesis: Aristotle’s Theory of Decision and its Legacy. Funded by a Leverhulme Major Research Grant


30. “Moral Theory in the Rhetoric” paper commissioned for Pierre Destrée and Laura Viidebaum (eds.), the Cambridge Critical Guide to Aristotle’s Rhetoric (CUP, est. submission 2024)

29. “Aristotle’s Ethics”, paper commissioned for Sophia Connell (ed.), New Cambridge Companion to Aristotle (CUP, est. submission 2024)

28. “The Magna Moralia on Prohairesis” to appear in Christopher Bobonich, Corinne Gartner and Martha Jimenez (eds.), Aristotle’s Other Ethics (OUP, 2023)

27. “Deliberation and Decision in the Eudemian Ethics”, in Giulio di Basilio (ed.), Essays on Aristotle’s Eudemian Ethics (Routledge, 2021)

26. “Guided Practice Makes Perfect: Habituation into Full Virtue in Aristotle’s Ethics”, in Komarine Romdenh-Romluc and Jeremy Dunham (eds.), Habit in the History of Philosophy (Routledge, 2021)

25. “Aristotle: Justice”, in K. Albrecht (gen. ed.), and J. Tasioulas (ed.), Encyclopedia of the Philosophy of Law and Social Philosophy (Springer Press, 2021)

24. “The Definitions of Phronêsis and Euboulia in Nicomachean Ethics VI”, in Carlo Natali and Pierre-Marie Morel (eds.), ‘Aristote. Les definitions en philosophie pratique’, special issue of Revue de Philosophie Ancienne, tome 38, no 2 (2020), pp 291-318

23. “Why Self-Knowledge Matters for Virtue”, in Fiona Leigh (ed.), Self-Knowledge in Ancient Philosophy (OUP, 2020), pp. 45-70

22. “The Tyrant’s Vice: Pleonexia and Lawlessness in Plato’s Republic”, Philosophical Perspectives (supplement to Nous), special issue on Ethics no 33 (2019), pp 146-69

21. “Deliberation and Decision in the Magna Moralia and Eudemian Ethics”, in Brink, Sauvé-Meyer & Shields (eds.), Virtue, Happiness and Knowledge: Essays for Gail Fine and Terence Irwin (OUP, 2018), pp. 197-215

20. “Spicy Food as Cause of Death: Coincidence and Necessity in Metaphysics E 2-3”, Oxford Studies in Ancient Philosophy vol. 52 (2017), pp. 303-42

19. “Vice in the Nicomachean Ethics”, Phronesis vol. 62, 1 (2017), pp. 1-25

18. “Aristotle”, in Timpe, Griffith and Levy (eds.), The Routledge Companion to Free Will (Routledge, 2016), pp. 227-235

17. “The Constitution of the Soul – Aristotle on Lack of Deliberative Authority”, Classical Quarterly, 65.2 (2015), pp. 572-86

16. “Introduction”, with Devin Henry, in D. Henry and K. M. Nielsen (eds.), Bridging the Gap Between Aristotle’s Science and Ethics (CUP, 2015), pp. 1-25

15. “Aristotle on Principles in Ethics”, in D. Henry and K. M. Nielsen (eds.), Bridging the Gap Between Aristotle’s Science and Ethics(CUP, 2015), pp. 29-48

14. “Aristotle on Economy and Private Property”, in Marguerite Deslauriers and Pierre Destrée (eds.), A Companion to Aristotle’s Politics (CUP, 2013), pp. 67-91

13. “The Will – Origin of the Notion in Aristotle’s Thought”, Antiquorum Philosophia 6 (2012), pp. 47-68

12. “The Nicomachean Ethics in Hellenistic Philosophy”, in Jon Miller (ed.), The Reception of Aristotle’s Ethics (CUP, 2012), pp. 3-30

11. “Ancient Ethics”, in H. LaFollette, S. Stroud and J. Deigh (eds.), The International Encyclopedia of Ethics (Wiley Blackwell, 2012)

10. “Deliberation as Inquiry: Aristotle’s Alternative to the Presumption of Open Alternatives”, The Philosophical Review, vol. 120, no 3 (2011), pp. 383-421

9. “The Good Will: Aristotle, Kant and the Stoics on What is Good without Qualification”, in S.Carson, J. Knowles and B. Myskja (eds.), Kant: Time, Space, and Ethics (Paderborn: Mentis Verlag, 2011), pp. 193-205

8. “The Private Parts of Animals: Aristotle on the Teleology of Sexual Difference”, Phronesis no 4-5, 2008, pp. 373-405

7. “Did Plato Articulate the Achilles Argument?” in Tom Lennon and Robert Stainton (eds.), The Achilles of Rationalist Psychology (Springer Press, 2008), pp. 19-42

6. “Dirtying Aristotle’s Hands? The Analysis of ‘Mixed Acts’ in Nicomachean Ethics, III, 1”, Phronesis no. 3, 2007, pp. 270-300

5. “Against Better Judgment? Davidson and Aristotle on Weakness of Will” in I et filosofisk terreng, Festskrift til Sverre Sløgedal, M. Dybvig, B. Molander, A. Øfsti (eds.) (Trondheim: NTNU, 2000), pp. 179-197

4. “Hvorfor begår mennesker onde handlinger?”, Interview with Prof. David Luban on Hannah Arendt’s Eichmann in Jerusalem – A Report on the Banality of Evil, Parabel, vol. III, no 1 (Trondheim: Tapir Publishers, 1999), pp. 77-86

3. “Hva er sannhet?”, Parabel, Journal for Philosophy and Theory of Science, vol. II, no 1 (Trondheim: Tapir Publishers, 1998), pp. 75-88

2. Hva er sannhet? — en studie i Martin Heidegger’s Sein und Zeit, Department of Philosophy Publication Series, no. 27 (Trondheim: NTNU, 1997)

1. “Tradisjon, sannhet og forståelse – en studie i Hans-Georg Gadamers hermeneutikk”, Agora, Journal for metafysisk spekulasjon, no 3 (1996), pp. 89-123


9. M. Deslauriers, Aristotle on Sexual Difference. Metaphysics, Biology, Politics (Oxford: Oxford University Press, 2022), in preparation for Archiv für Geschichte der Philosophie (2024)

8. C. Olfert, Aristotle on Practical Truth (Oxford: Oxford University Press, 2017), Philosophical Review (2019) 128 (2), pp. 219-224

7. A. Kenny, The Aristotelian Ethics, revised ed. (Oxford: Oxford University Press, 2017), Classical Review 68.2 (2018)

6. D. Scott, Levels of Argument (Oxford: Oxford University Press, 2015), review essay, Mind (2016), pp. 289-99

5. H. J. Curtzer, Aristotle and the Virtues (Oxford: Oxford University Press, 2012), review essay, Mind (2014), 1180-4

4. J. Miller, Aristotle’s Nicomachean Ethics: A Critical Guide (Cambridge: Cambridge University Press, 2011), Journal of Hellenic Studies, 2013, pp. 290-91

3. S. Goetz and C. Taliaferro, A Brief History of the Soul (Wiley-Blackwell, 2011), review essay, Notre Dame Philosophical Reviews, April 16, 2012. (with Angela Mendelovici)

2. G. Pearson and M. Pakaluk (eds.), Moral Psychology and Human Action in Aristotle (Oxford: Oxford University Press, 2011), Polis, The Journal of the Society for Greek Political Thought, vol. 29, no 1 (2012), pp. 199-205

1. H. Lorenz, The Brute Within: Appetitive Desire in Plato and Aristotle (Oxford: Oxford University Press, 2006), Journal of the History of Philosophy (2008), pp.477-8

Where Next?