Derek Allen



In memoriam


St. George,

Phone Number:



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

Derek Allen (1947-2023) joined the University of Toronto in 1973 and had a long and distinguished career here. Since his time as a student (he received his BA in 1969) he was very involved with Trinity College, serving in various administrative roles in the College over his long career, including Dean of Arts. Allen completed his MA at the University of Toronto in 1972 and received his DPhil from Oxford in 1979. In 2015 he retired after 42 years of service to the University.

Research Interests:

Critical Thinking, Ethics, Informal Logic, Marxism


  • 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.