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Geoffrey Chaucer's The Canterbury Tales is a time-honor masterpiece that was a first in several ways; perhaps the most important is that he wrote in the Middle English as opposed to Old English, making his work available to a much wider audience. Chaucer was the first major author to do so.
Chaucer also writes a collection of stories told in the voice of different characters, using a pilgrimage to the site of the martyred Thomas Beckett as a framework—which is a literary structure that provides a situation where members of many different social classes are joined together. (This would have been one of the few, perhaps the only, circumstances where the members of this very diverse group would intermingle.) The premise is that as the groups stops each night, one of the travelers must tell a tale to entertain the rest. Each character is described separately, and then has a tale to tell which often reflects on the storytelling character's personal traits. The Host of the group promises the person telling the best tale by the end of the journey a free meal.
Chaucer's ability to speak with so many "voices" is due to the variety of positions he held which enabled him to move in the highest social circles as well as lower circles. He is often referred to as a student of human nature: one who has observed people from all walks of life, making note of their actions: the noble, the pious and the hypocritical.
Chaucer drew on real life for his cast of pilgrims...The many jobs that Chaucer held in medieval society—page, soldier, messenger, valet, bureaucrat, foreman and administrator—probably exposed him to many of the types of people he depicted in the Tales. He was able to shape their speech and satirise their manners in what was to become popular literature among people of the same types.
Harry Bailly, the self-appointed host of the pilgrimage, then asks the priest, Sir John, for a change of pace, a “merry” tale.
The Nun's priest then tells the tale of a prideful rooster, Chanticleer, who is almost killed by the predatory fox who tricks the egotistical rooster into delivering himself into the "hands" of the fox, who then is confounded when Chanticleer does the same to him.
The priest acts simply as the storyteller for this tale. He is a good person to tell the story, as he is a pious man telling a moral fable— which was not an uncommon way of delivering a message at the time, as opposed to preaching a sermon. He is warning against the dangers of being too proud, and pride is not something he is seemingly guilty of. He is not being hypocritical with his tale, as several other of the members of the Church on this trip are. His only "fault" is that he ends up telling the same kind of tale that the Monk did, dealing with a fall—though it is more like the fall of Adam and Eve; but still the fable is humorous rather than tragic, and therefore more "merry" indeed.