What was the purpose of satire in the canterbury tales

Chaucer uses satire in the descriptions of the pilgrims in the "General Prologue" of The Canterbury Tales to reveal corruption in the Church that was prevalent in society.  Many members of the clergy used their positions for personal gain.  This can be seen in his cast of characters.  Of all the pilgrims associated with the Church, the Parson is the only one who is honorable.