In 1965 he became an assistant professor in the French department of the University of Manitoba in Winnipeg, Canada.
[3] He was the author of books including Surrealism: Permanent Revelation (1970, with Robert Short) [4] and Outsider Art (1972),[5] and was professor of literary and visual studies at the University of Kent.
In 1979 he and Victor Musgrave curated Outsiders at the Hayward Gallery, London.
Cardinal published widely on individual outsider artists and wrote essays on outsider architecture, prison art, autistic art, and memory painting.
[7] Cardinal was also on the International Jury of the INSITA Triannual Exhibition, held in Slovakia.