Dear Shanks: Using your clues, search for "Chaucer Pardoner cupiditas" yielded:
"Moreover, a careful reading of The Pardoners Tale shows that it is an apposite illustration of major Augustinian themes, especially those expounded in the early, obscure treatise On Lying. The Pardoners avowal that his main theme is the Pauline aphorism Radix Malorum est cupiditas (334, 426, I Timothy 6:10) and subsequent description of his modus operandi have thrown many critics off the scent of what truly ails and peynes (330) his character."