I was born and grew up in the United Kingdom in a family of musicians and teachers before emigrating, first to Canada, then to the United States. During the late 1970s and early 1980s, I was privileged to study English literature at Cambridge University with Arthur Sale, Richard Luckett and John Stevens, and medieval literature at Oxford with Pamela Gradon, Anne Hudson, Douglas Gray, and Vincent Gillespie. I then wrote a PhD at the University of Toronto as a Connaught Fellow under the practical and sensitive direction of Denton Fox and George Rigg, which I completed in 1987. In the mid to late 1980s, I was adjunct lecturer at the Memorial University of Newfoundland and briefly at the University of Calgary, Trent University and McMaster University, and held postdoctoral fellowships at Memorial and McMaster, before in 1990 becoming Assistant Professor of English at the University of Western Ontario, where I taught for ten years. From 1985 to 1989, I also played first violin in the Newfoundland Symphony Orchestra and was principal violin of the Terra Nova Chamber Players.

While at Western, I published four books: a monograph Richard Rolle and the Invention of Authority (1991) based on my PhD thesis, for Cambridge Studies in Medieval Literature; a critical translation, Anchoritic Spirituality: Ancrene Wisse and Associated Works (1991) with Anne Savage, for Paulist Press's Classics of Wesrtern Spirituality series; a single-manuscript edition, Richard Rolle's Emendatio Vitae and Orationes ad honorem nominis Ihesu (1995), for Toronto Medieval Latin Texts; and The Idea of the Vernacular: An Anthology of Middle English Literary Theory, 1280-1530 (1999), with Ruth Evans, Andrew Taylor, and Jocelyn Wogan-Browne, for Penn State Press and Exeter University Pess. I published a number of articles, some focused on the English visionary Julian of Norwich, whose writings I began to edit, others on an approach to Middle English religious writing in general via the term and concept "vernacular theology." One article, "Censorship and Cultural Change in Late Medieval England: Vernacular Theology, The Oxford Translation Debate, and Arundel’s Constitutions of 1409" (1995), proved controversial enough subsequently to serve as a springboard for a major conference, "After Arundel," held in Oxford in 2009. In 1991, I inadvertently discovered a work or vision, rituals, and experiments called Liber florum doctrine celestis by a northern French Benedictine monk, John of Morigny, previously known only through a record of its condemnation for heresy in 1323, and began work on an edition and study with Claire Fanger. Later in the decade, with Richard Hillman, Laurence de Looze, Richard Firth Green, and especially Fiona Somerset, I also mounted a series of interdisciplinary conferences, including "The Cultural Work of Ritual, Symbol, and the Other" (1995) and "Vernacularity: The Politics of Language and Style" (1999). Several students I taught at Western went on to university careers; others teach in high schools or in the CEGEP (Collège d'enseignement général et professionnel) system in Quebec.

In 2001, I moved to Harvard University as Professor of English, later Henry B. and Anne M. Cabot Professor of English, where I have served as director of graduate studies director of undergraduate studies, and department chair. Besides serving on the Standing Committee on the Study of Religion, I have several times been chair of the Standing Committee on Medieval Studies, as this network of scholars and students has worked to sustain the study of the human past and to advocate for its importance to the university's intellectual and societal mission. I have also been advisor on more than twenty PhD dissertations and five undergraduate senior theses. Former students have gone on to careers as university professors, high school teachers, novelists, and more.

Much of my first decade at Harvard was spent completing earlier projects: an essay collectionThe Vulgar Tongue: Medieval and Postmedieval Vernacularity (2004), with Fiona Somerset, for Penn State, based on the 1999 "Vernacularity" conference; Writings of Julian of Norwich: A Vision Showed to a Devout Woman and A Revelation of Love (2005), with Jacqueline Jenkins, for Penn State and Brepols; and Liber florum doctrine celestis / The Flowers of Heavenly Teaching: An Edition and Commentary (finally published in 2015), with Claire Fanger, for PIMS. Since 2010, I have co-edited four more books, including a festschrift for Richard Firth Green,Truth and Tales: Cultural Mobility and Medieval Media (2014), with Fiona Somerset, for Ohio State; Studies in Middle English Literature in Honor of David Benson, with Daniel Donoghue, Susanna Fein, David Raybin, and James Simpson, for The Chaucer Review and Penn State; The Practics and Politics of Reading, 650-1500, with Daniel Donoghue, James Simpson, and Anna Wilson (2022), for D. S. Brewer; and What Kind of A Thing is A Middle English Lyric? (2022), for U Penn Press. These four books were based on conferences or workshops held at Toronto, Harvard (x2), and the Radcliffe Institute of Advanced Study respectively. Other conferences, such as "Conversion" (2004) and "Medieval / Africa: The Trans-Saharan World, 500-1700" (2015), the latter co-organized with Sean Gilsdorf at Harvard in association with the Committe on Medieval Studies, the Center for African Studies and the Hutchins Center, have been equally fruitful but have not resulted in publications.

Current projects include a translation of John of Morigny's Liber Florum with Claire Fanger, and a comparative study of the works of two great early English women visionaries, The Lowest Part of Our Need: Julian of Norwich and Margery Kempe, which aspires to show in detail how these works were put together and which I am presently working on in the form of occasional articles. Over the past fifteen years (and counting), however, much of my research energy has been dedicated to conceptualizing and writing what has grown into a monograph in three, long volumes, Balaam's Ass: Vernacular Theology Before the English Reformation. Having written some thirty articles towards this project and given innumerable talks and papers, the first volume of this book, subtitled Frameworks, Arguments, English to 1250, was at last published by U Penn Press in 2022. The second, subtitled French 1100-1400, English 1250-1540 is nearing completion; much of the third, subtitled The Mystical Ark: Salvation, Conversion, Community, is still in the development stage.

Throughout my career I have been deeply privileged in my teachers, colleagues and students, and more pointedly in the resources made available to my research, not least in the form of fellowships. My work in Canada was supported by the Social Sciences and Humanities Research Council of Canada, which awarded me two postdoctoral fellowships and several research awards, as well as by the John Charles Polanyi Prize foundation. My work in the United States has been supported by the Radcliffe Institute of Advanced Studies, the American Council of Learned Societies, the Princeton Institute of Advanced Studies, and the Guggenheim Foundation, as well as by several sabbaticals awarded me by Harvard, one of them spent as a visiting professor at Oxford. In 2017, I was elected Fellow of the Medieval Academy of America. I will continue to try to repay the debt I owe my scholarly communities: through service to my students and colleagues; through the work I do for professional organizations such as the Medieval Academy and the International Piers Plowman Society; through organizing conferences open to scholars at all career stages; and through publications that support, while also attempting to keep up with, the research and teaching of others.