"A Tale of a Tub" was the first major work written by Jonathan Swift, composed between 1694 and 1697 and published in 1704. It is arguably his most difficult satire, and perhaps his best. The Tale is a prose parody divided into sections of "digression" and a "tale" of three brothers, each representing one of the main branches of western Christianity.
Swift wrote "A Tale of a Tub" not only to expound upon the hypocrisy of religion in early 18th century England, but to explore ideas about critics, oration, ancient and modern philosophies, digressions, and the nature of writing itself. These themes are all underscored with a satirical tone that takes religion, authors, and critics to task. The title refers to the tub that sailors used to toss out to distract whales from tipping their ships. The ship represents the status quo of the English government and its religious structure, while the whale is a symbol for the new ideas and controversies attempting to rock the ship: The government must keep dissent like Swift's at bay.
Although it's been suggested that Swift intended to write a piece that was supportive of Protestantism (he was a clergyman in the Church of England), the structure of the piece and the consistent use of satire made it seem like he was denouncing all religion. The Anglican Church disapproved of his treatise, as did the monarchy. Even though he avoided admitting authorship of the piece, many assumed he had written it and it stunted his rise in the Church. A satire on the Roman Catholic and Anglican churches and English Dissenters, it was famously attacked for its profanity and irreligion. The work continued to be regarded as an attack on religion well into the nineteenth century.