Born on February 27, 1927 in Milwaukee, Wisconsin, Quesnell earned a Master's Degree in Philosophy and an STL from St. Louis University. He later did studies in eastern languages and the Bible in Vienna, Paris, Jerusalem, and Rome. After receiving a PhD in Sacred Scriptures from the Pontifical Biblical Institute, he joined Marquette University as a professor (1966 - 1972). He left Marquette for Smith College, becoming the head of the Department of religion from 1975 until 1997. During his time at Smith, Quesnell met fellow professor Jean Higgins and the two married in 1973. After retirement in 1997, he was awarded the Roe Straut Professor Emeritus (Roe Straut Professor of Humanities, 1988).
Quesnell actively engaged in several scholarly debates throughout his lifetime but is most known for his role in the Mar Saba Letter debate and his subsequent high-profile disputes with the discoverer letter, Morton Smith (1915 - 1991). In 1973 Smith published two books on his discovery of a previously unknown letter written by Clement of Alexandria to "Theodore" regarding a secret gospel of Mark. Quesnell's initial skepticism of the authenticity of this discovery sparked a 30-year debate within the academic community.
From the guide to the Quentin Quesnell papers RG 42., 1927 - 2012, 1970 - 2000, (Smith College Archives)
