Therfore my theme is yet, and evere was,
Radix malorum est Cupiditas.
– Geoffrey Chaucer
The Canterbury Tales, The Pardoner’s Prologue. So the Pardoner reveals that the theme of his tale is the biblical teaching "Radix malorum est Cupiditas" or "Greed is the root of all evil." And that is one of the Seven Deadly Sins he knows a lot about, as he makes a practice of it in his trade.