Derek Allen



Emeritus Professor


St. George,

Phone Number:



  • BA, MA, University of Toronto
  • BPhil (now MPhil.), DPhil, University of Oxford

Research Interests:

Critical Thinking, Ethics, Informal Logic, Marxism


Selected, Recent:
  • Validity. In J. Anthony Blair (Ed.) Studies in Critical Thinking, 2nd edition, 37-49 (2021). Windsor, ON: Windsor Studies in Argumentation.
  • Allen, D., Bailin, S., Battersby, M. & Freeman, J. Critical Thinking. In Oxford Research Encyclopedia of Education (2020). New York: Oxford University Press. (Online; no page numbers).
  • Justification in ethics. In J. Anthony Blair & Christopher W. Tindale (Eds.), Rigour and Reason: Essays in Honour of Hans Vilhelm Hansen, 143-173 (2020). Windsor, ON: Windsor Studies in Argumentation.
  • Evidence, Persuasion and Diversity. Informal Logic, 40(2), 237-254 (2020). A slightly revised version of a keynote address given at an international virtual conference of the Ontario Society for the Study of Argumentation, June 2020.
  • “Wohlrapp’s Concept of Justification.” Informal Logic, Vol. 37, No 3 (2017).
  • “Aboriginal Title and Sustainable Development: A Case Study.” Forum on Public Policy, Vol. 2016, No 2.
  • “The very idea of ethical arguments.” International Society for the Study of Argumentation, Proceedings 2014.
  • “Trudy Govier and Premise Adequacy.” Informal Logic, 33(2), 2013: 116-42.
  • “Conductive Arguments and the Toulmin Model: A Case Study.” In J.A. Blair & R.H. Johnson (Eds.), Conductive Argument: An Overlooked Type of Defeasible Reasoning, 167-90. Studies in Logic: Logic and Argumentation, Vol. 33. London: College Publications, 2011.