Money is stigmatized in this chapter as gunpowder was in the last. It is a medium whereby people can satisfy their vices and extend their misuse of reason. Swift draws on a theory that Bernard Mandeville made popular in his Fable of the Bees. Mandeville held that private vices increased business; thus private vices were public virtues. In Swift's view, private vices are no excuse for money-making; they constitute a vicious circle. To him, private vices are public vices.
Diet symbolizes these public vices which are pandered to by money. Great sums of money enable people to eat so-called gourmet foods in extravagant quantities. Such a diet is not necessary; indeed, it undermines health. Simple fare is far better. Yet expensive gourmet food is a status symbol. This artificially valued, unwholesome diet is thus paralleled with the naturally unwholesome fare of the Yahoos.
This chapter is one of the most complex, but one of the most unified, in the book. Swift starts with money and luxury, linking these to health and morality. He then uses doctors to associate disease with politics. Doctors can kill their patients; and the poisons that medicine has discovered can sometimes be "useful" to politicians. Finally, he links disease and luxury to the entire nation by describing the genetic defects and venereal diseases of the nobility, who marry for political and commercial reasons.
