During the Middle Ages, religion was the matrix of a persons life. Everything, even boiling an egg, depended on religion, for the egg was cooked when the prayer was finished. With religion came certain morals and ideals that even now are associated with Christianity. A person was viewed based on how he measured up to the ideals of his profession or position in life. This was mostly proven in the satiric tone that Geoffrey Chaucer chooses to give to the narrator, in the Prologue, when describing such corrupt characters as the Monk and the Pardoner.
The Millers Tale further illustrates this point by showing that a person who does not follow the ideals that are set up for him by birth and religion, will be punished for his sins. John the Carpenter is a good man, but he makes a mistake by marrying a woman who is two times younger than he is. Because his young bride is beautiful and lively, jealous he was and kept her in a cage . . . Jealousy is a sin and therefore, he is not living up to the ideals that the world had set out for him. By the end of the tale, the Carpenter is punished for his imperfections.
With the help of Nicholas and Alison, the wife of the carpenter, all of the town thinks that the Carpenter is crazy. Because he sins by being jealous, this public humiliation is his punishment. Nicholas the Gallant is punished for several things. He lusts after a married woman. He uses his knowledge of the stars and the study of astrology, to his own advantage and to the disadvantage of another, namely the Carpenter. He is not an honorable man like men of that time were supposed to be, because he insults and assaults another person. For this, Nicholas is punished by the branding he receives on his arse.
Absalon is also declining from his duties to God and the society, which are to be courteous and honorable and not sin. Like Nicholas he is lusting after Alison. Not only was that a sin because Alison is married, but also because lust in general is one of the deadly sins. Furthermore, he works for the church, which means that his moral level should be high and he is supposed to be setting the example for the rest of the people around him, so he should be judged more harshly than any man of the secular world. For this, Absalon had kissed her [Alisons] nether eye, and also Nicholas.
He also received an unpleasant bodily gas in his face. This works perfectly as a punishment because he is squeamish and acts more like a woman, of his time, than a man. Alison, the beautiful, young bride of John the Carpenter, commits adultery by cheating on her unsuspecting husband with Nicholas, and although women were thought of as failed males in the Middle Ages, she is also punished. It seems that the standards that Chaucer had for her were not as high as for the other characters. This could be because women did not have to be chivalrous, even today this is thought of as a male characteristic.
Nonetheless, the town knew about her affair with Nicholas and could have done anything from just gossiping about her to killing her for heresy. All these characters and their sins and punishments, lead up to the moral of the story, or the theme; a sin never goes unpunished. Each character described represents a small section of the society of those times. This also shows the set in of corruption during the Middle Ages, later to reach its zenith with the Babylonian Captivity, and the fall of the church in the eyes of man.