I am a Junior Research Fellow in Philosophy at Merton College, Oxford University. My research focuses on contemporary theories of liberalism. In particular, I am interested in various principles of liberal political morality, such as the harm principle, the principle of state neutrality, and the public justification principle.

I received a DPhil in Philosophy from St John's College, Oxford University in 2019. During the DPhil, I was a Lecturer in Political Theory at Christ Church, Oxford University. Prior to the DPhil, I read the BPhil in Philosophy at The Queen's College, Oxford University (2015-17) and an undergraduate degree in Philosophy, Politics and Economics at Lincoln College, Oxford University (2012-15).

Email: collis.tahzib@philosophy.ox.ac.uk


1. "Perfectionist Duties", in D. Sobel, P. Vallentyne and S. Wall (eds), Oxford Studies in Political Philosophy Volume 7 (Oxford: Oxford University Press, forthcoming). 

2. "Does Edificatory Perfectionism Express a Quidnunc Mentality?", in V. Kurki and M. McBride (eds), Without Trimmings: The Legal, Moral, and Political Philosophy of Matthew Kramer (Oxford: Oxford University Press, forthcoming). 

3. "Do the Reactive Attitudes Justify Public Reason?" European Journal of Political Theory (forthcoming).

4. "Perfectionism: Political not Metaphysical", Philosophy & Public Affairs 47 (2019), pp. 144-78.

5. "Pluralist Neutrality", The Journal of Political Philosophy 26 (2018), pp. 508-32. 

Recent talks

1.   "Perfectionist Principles of Justice" at University of Rijeka, February 2020.

2.   "Deontic Perfectionism" at University of Southern California, January 2020.

3. "Deontic Perfectionism" at 7th Annual Workshop for Oxford Studies in Political Philosophy, Syracuse, NY, August 2019.

4. "Does Edificatory Perfectionism Express a Quidnunc Mentality?" at Conference in Honour of Matthew Kramer, Cambridge, July 2019.