Clothier was born in Newcastle upon Tyne and spent his early years in English country villages.

He went on to attend Gonville and Caius College, Cambridge, graduating in 1958 with a BA in Modern and Medieval Languages and French Philology.

While attending the workshop, he embarked on a PHD course in Comparative Literature and completed a dissertation on Contemporary French Poetics in 1969.

He left Otis in 1979 in order to accept a Rockefeller Fellowship for a study of the life and work of the pioneering African American artist Charles White.

[4] From 1983 to 1985, Clothier served as Dean of the College of Fine & Communication Arts at Loyola Marymount University.