Why are Lagadonian Languages so Called?

A Lagadonian language is a language where objects and properties can be names for themselves (Lewis 1986: 145). But why are Lagadonian languages so called? The answer can be found in Jonathan Swift's Gulliver's Travels from 1726 (thanks to John Gabriel).

In Gulliver's Travels, Swift's hero Lemuel Gulliver visits the Academy of Science at Lagado, the capital city of Balnibarbi. Here he finds scientists trying to extract sunbeams from cucumbers, erect buildings from the roof down, plow farmland with pigs, and make marbles soft enough to stuff pillows. At the school of languages a language experiment is being conducted. Gulliver explains (pp. 162-3):

"The other project was a scheme for entirely abolishing all words whatsoever; and this was urged as a great advantage in point of health as well as brevity. For it is plain that every word we speak is, in some degree, a diminution of our lungs by corrosion; and consequently contributes to the shortening of our lives. An expedient was therefore offered, that since words are only names for things, it would be more convenient for all men to carry about them such things as were necessary to express the particular business they are to discourse on. And this invention would certainly have taken place, to the great ease as well as health of the subject, if the women, in conjunction with the vulgar and illiterate, had not threatened to raise a rebellion, unless they might be allowed the liberty to speak with their tongues after the manner of their forefathers; such constant irreconcilable enemies to science are the common people".

"However, many of the most learned and wise adhere to the new scheme of expressing themselves by things; which hath only this in­convenience attending it, that if a man's business be very great, and of various kinds, he must be obliged, in proportion, to carry a greater bundle of things upon his back, unless he can afford one or two strong servants to attend him. I have often beheld two of those sages almost sinking under the weight of their packs, like pedlars among us; who, when they met in the streets, would lay down their loads, open their sacks, and hold conversation for an hour together; then put up their implements, help each other resume their burdens, and take their leave".

"But, for short conversations, a man may carry implements in his pockets, and under his arms, enough to supply him; and in his house he cannot be at a loss. Therefore the room where company meet, who practise this art, is full of all things ready at hand, requisite to furnish matter for this kind of artificial converse".

"Another great advantage, proposed by this invention, was, that it would serve as a universal language, to be understood in all civilised nations, whose goods and utensils are generally of the same kind, or nearly resembling, so that their uses might easily be comprehended. And thus ambassadors would be qualified to treat with foreign princes, or ministers of state, to whose tongues they were utter strangers".

Swift's novel was a satire on various aspects of humanity. But satire or not, Lagadonian languages have proven useful to modal abstractionists, or ersatzers, as David Lewis called them, those who treat possible worlds as abstract entities. As a nice example of how Lagadonian languages can be used to describe possibilities and possibilia, take a look at, for example, Ted Sider's The Ersatz Pluriverse.

Reference
Lewis, David. 1986. On the Plurality of Worlds. Cambridge: Blackwell.