"A Joke's A Very Serious Thing"

Context: Charles Churchill was a dissipated clergyman who won for himself both fame and notoriety as a satiric poet during the last few years of his life. Much of the character of his verse seems to have been determined by his association with the unscrupulous editor of the North-Briton, John Wilkes. The story of the Cock Lane Ghost broke in 1762 when William Kent was accused of having committed adultery with and subsequently murdering his sister-in-law, Fanny Lynes. The accusation was made by Richard Parsons, whom Kent had sued for debt, and the evidence was the testimony of Fanny's ghost given through Parsons' daughter as a medium. Kent appealed to the courts to vindicate his character, and a commission including Dr. Samuel Johnson investigated the affair and pronounced it all a fraud. The affair was a very popular butt for satirists, including the dramatists, and Churchill's somewhat rambling comic treatment extends to four books. Book IV rambles even more discursively, if possible, than Book III, digressing frequently into political satire. One of the bitterest attacks is upon Lewis Bruce, as Crape, who had been given a clerical promotion which Churchill had expected to receive:

Nor think a joke, CRAPE, a disgrace
Or to my Person, or my place;
The wisest of the Sons of Men
Have deign'd to use them now and then.
. . .
Great Use they have, when in the hands
Of One, like me, who understands,
Who understands the time, and place,
The persons, manner, and the grace,
Which Fools neglect; so that we find,
If all the requisites are join'd
From whence a perfect joke must spring,
A joke's a very serious thing.