Chaucer makes the statement that greed leads to deception by focusing his tales on realistic problems of the time, arguing that, those who deceive deserve to be punished.
In the Millers Tale, Alison and her lover Nicholas preoccupy Old John by convincing him that a huge flood approaches in order to be alone for the night, by Old John bearing the blame and punishment, Chaucer illustrates that the marriage of someone younger foretells a disastrous marriage. Old John, whose wit was ride, ignores Catouns social rule that bad man sholde wedde his similitude, therefore Old John deserved the scalding on the bum, becoming the laughing stalk of the town and being considered a cokewald. Old John chose to marry Allison despite the known consequences that lied ahead, he expected her to cheat so by keeping her on a short leach due to greed and jealously, he contributed to her wild youthful nature, thus John must bear the blame for his selfishness and refusing to acknowledge her inevitable betrayal.
The Reeves Tale continues the theme of deception with the idea that, tricksters deserve punishment for their actions, when Alan and John need their grain to be ground they go to Symkyn, a miller notorious for his greed, they watch him carefully but Symkyn manages to deceive them despite their precautions. The miller let Alan and Johns horses escape, so while stranded at the millers house, so Alan and John slept with Symkyns daughter and wife, Alan and John are justified in this act because, a gylour shal himself bigyled be and Symkyns punishment is being hit on the head and having an unfaithful wife and daughter. Although sleeping with Symkyns wife and daughter may be more severe than stealing grain, they finally stood up to Symkyn, a man who frequently gives into his greed and deceives the whole town, people feared him, so by teaching him a lesson Alan and John are worthy of praise rather than punishment.
In the Pardoners tale, three friends take an oath to live and dyne ech of hem for other, and went from town to town in search of and answers about the thief called death; when they break the oath and gold tears their friendship apart, it becomes clear that Chaucers believes that greed caused the betrayal. Before the Pardoner begins his tale, he warns, Radix malorum est Cupiditas, however the three rakes, blinded by their greed and in a attempt to deceive each other; the youngest gets stabbed and the other two get poisoned. The greed that infected the three friends caused them to deceive one another for their own monetary gains; they broke their oath and deservedly suffered the same punishment that they planned to inflict on each other, death.
Chaucers shows the evils of greed and deception in society at the time by illustrating the consequences, he says that those who deceive deserve to be punished, so ultimately, Chaucer wants genuine honesty in society.