- Emeritus Fellow, All Souls College (from 1997 to 2023)
- President, Pontifical Institute of Mediaeval Studies, Toronto (from 1996 to 2008)
- Research Fellow, All Souls College (from 1990 to 1997)
- President and Vice-Chancellor, University of St Michael’s College, Toronto [now Emeritus] (from 1984 to 1990)
- Research Fellow, All Souls College (from 1980 to 1984)
- Junior Fellow (Professor extraordinarius) then Senior Fellow (Professor ordinaries), Pontifical Institute of Mediaeval Studies, Toronto (from 1967 to 1991)
- Part-time instructor, Division of Humanities, York University, Toronto (from 1963 to 1964)
- Instructor in History, then Assistant Professor, University of Saskatchewan (from 1956 to 1962)
- Erasmus
- Intellectual history
- Historical theology
- English Humanists and Reformation Politics (Oxford: Oxford University Press, 1965).
- 'Erasmus and the Grammar of Consent', in Joseph Coppens (ed.) Scrinium Erasmianum (Leiden: Brill, 1969).
- 'The Prosopography of Tudor Oxford', Journal of Interdisciplinary History (1973).
- 'Erasmus and the "Julius": a Humanist Reflects on the Church', in Studies in Medieval and Reformation Thought X (Leiden, 1974).
- 'Scholars and Commoners in Renaissance Oxford', in Lawrence Stone (ed.) The University in Society (Princeton: Princeton University Press, 1974).
- The Correspondence of Erasmus - Letters 298 to 593: 1514 to 1517, translated by R.A.B. Mynors and D.F.S. Thomson, annotated by James K. McConica (Toronto; Buffalo: University of Toronto Press, 1976 and 1977).
- Volumes 3 and 4 of Collected Works of Erasmus (Toronto: University of Toronto Press).
- Thomas More: A Short Biography (London: Her Majesty's Stationery Office, 1977).
- 'Humanism and Aristotle in Tudor Oxford', English Historical Review 94 (1979).
- The Collegiate University, volume 3 of The History of the University of Oxford (Oxford: Oxford University Press, 1986).
- Erasmus (Oxford: Oxford University Press, 1991).
- 'The Early Fellowship' and 'Warden Hovenden' in Unarmed Soldiery, Studies in the Early History of All Souls College Oxford. The Chichele Lectures 1993-1994. (Oxford: All Souls College, 1996).
- ‘Edgar Winds Oxforder Jahre’ in Horst Bredekamp et al., Edgar Wind, Kunsthtoriker und Philosoph (Berlin: Akademie Verlag, 1998).
- ‘L’enseignement humaniste à Oxford et à Cambridge et l’influence d’Erasme en Angleterre’, in André Tuilier (ed.) Histoire du Collège de France (Paris: Fayard, 2006).
- 'The Englishing of P. S. Allen' in Erasmus and the Renaissance Republic of Letters ed. Stephen Ryle (Turnhout: Brepols, 2014).
- Publications (External Link)
- Honorary Fellow, Exeter College, Oxford
- Member, International Commission on English in the Liturgy (from 2002)
- Member (Vice-President, 1998–), International Council directing the Opera omnia of Erasmus of Rotterdam (ASD) under the auspices of the International Union of Academies and the Royal Dutch Academy (from 1983)
- Chairman, Editorial Board, Collected Works of Erasmus, Toronto (from 1975)
- Member, Board of Trustees, University of Toronto Art Centre (from 2003 to 2005)
- Chair, Medieval Studies Foundation, Toronto (from 1996 to 2008)
- Director, Canadian Rhodes Scholars’ Foundation (from 1997 to 2008)
- Visiting Fellow, All Souls College (1969–71 and 1977)
- Foreign Member, Royal Belgian Academy
- Honorary Fellow, Huntingdon Library (1976)
- Corresponding Member, British Academy
- Corresponding Member, Royal Belgian Academy
- Officer of the Order of Canada
- Lifetime Achievement Award (2006).