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.

I have published on Aristotle’s metaphysics, and like to explore first-order philosophical questions in the course of analysing and assessing Greek texts. My papers cover topics ranging from deliberation and its preconditions, compulsion and voluntariness, coincidence and necessity, Aristotle’s developmental biology, virtue and vice.
A note on my name: I use both my first names (‘Karen Margrethe’) as if there was a hyphen. Oxford email doesn’t recognise Scandinavian naming practices, so my second first name was not included in my email address. If you find the cluster of consonants in ‘Margrethe’ hard to pronounce, I’m fine with ‘Karen’.  In print, my full name should appear as ‘Karen Margrethe Nielsen’, not ‘Karen Nielsen’. 

Career & Education

2013 – present: Associate Professor, Faculty of Philosophy, and Tutorial Fellow, Somerville College, University of Oxford

2005-12: Associate and Assistant Professor, Department of Philosophy, Western University, Canada

2006: PhD Sage School of Philosophy, Cornell University

1997: M.A., Department of Philosophy, Norwegian University of Science and Technology

1995: B.A. Philosophy, Greek, History of Ideas, Norwegian University of Science and Technology


Recent graduate seminars

  • 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, combined undergraduate and graduate seminar, TT 2014


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


  • Aristotle’s Nicomachean Ethics, Latin Philosophy



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

Reviewed in: Journal of the History of Philosophy (Emily Katz); Bryn Mawr Classical Review (Sophia Connell); The Classical Review (Anthony Price); Notre Dame Philosophical Reviews (Brennan McDavid)); Classical World (Wolfgang Mann)


2. Prohairesis: Aristotle’s Theory of Decision and its Legacy

3. Vice in Ancient Philosophy: Plato, Aristotle, and the Stoics, commissioned for James Warren (ed.), Elements in Ancient Philosophy series (Cambridge: Cambridge University Press) Under contract.


1. “The Magna Moralia on Prohairesis” commissioned for Christopher Bobonich, Corinne Gartner and Martha Jimenez (eds.), Aristotle’s Other Ethics, submission deadline April 2022

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

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

4. “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

5. “Why Self-Knowledge Matters for Virtue”, in Fiona Leigh (ed.), Self-Knowledge in Ancient Philosophy, volume based on 2009 Keeling Colloquium (Oxford: Oxford University Press, 2020), pp. 45-70

6. “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

7. “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 (Oxford: Oxford University Press, 2018), pp. 197-215

8. “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

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

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

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

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

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

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

15. “The Nicomachean Ethics in Hellenistic Philosophy”, in Jon Miller (ed.), The Reception of Aristotle’s Ethics (Cambridge: Cambridge University Press, 2012), pp. 3-30

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

17. “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

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

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

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

21. “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

22. “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, Journal for Philosophy and Theory of Science, vol. III, no 1 (Trondheim: Tapir Publishers, 1999), pp. 77-86

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

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

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


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

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

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


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

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

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

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

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

6. 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)

7. 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

8. 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?