While English is the most widely-spoken lingua franca in history, so-called common or working languages can be much less pervasive. Elamite, for example, was the submerged administrative language of the Persian Empire in the sixth century B.C.E. All official documents were written down in Elamite, but they were both composed and read out in Persian, the language of the illiterate ruling class. Then there is Pali, the language of Theravada Buddhism. No longer used in everyday conversation, Pali is written in different scripts in Sri Lanka, Cambodia, and Burma, and sounds different when read aloud by Thai and Burmese speakers. The identity of the language is almost obscured by its profusion of forms.

Pali is a tantalizing case for Nicholas Ostler, because it suggests to him the possibility of a “virtual” language. A “virtual language” would not be read or spoken itself. It would allow the user to understand what is being written or said without learning the original language—in much the same way that “virtual reality” allows the user to have an experience of something without actually doing it. Pali is not “one language” in the concrete sense that it has one set of words, but those who know any of its forms can access exactly the same information. Yet on closer inspection this is not because it is a “virtual language.” It is because the differences between its forms are largely superficial. However the words are pronounced or written down, they mean the same thing. It is one language after all.

Despite this setback, Ostler has faith in a virtual system, which he claims will revolutionize global communications, and make foreign language learning a thing of the past. The traditional culture of Theravada Buddhism may not be the most receptive context for such radical change, but the internet serves as a low-cost, low-risk testing ground for new translation technologies. Google Translate, Babel Fish, and Microsoft’s Bing Translator all offer instant, automatic translation across a range of languages, and are constantly expanding their services. The results are often riddled with mistakes, sometimes amusingly. But Ostler believes that improvements in the technology will eventually “remove the requirement for a human intermediary to interpret or translate.” Printed texts and recorded speeches will be accessible to anyone with the right software as “virtual media.”

It is a bold vision of the future, and a particularly attractive one to Ostler, who is chairman of the Foundation for Endangered Languages. A technological revolution could save declining tongues from extinction. Those who now neglect their traditional regional language in favor of English would no longer need a lingua franca to access the same commercial and cultural opportunities. For Ostler, this is not just a desirable outcome. It also affirms “the social order created by mother tongues, where each community has its own language, as if by nature.” He does not admit the irony that this natural order could only be enforced by digital means, but the belief in its enduring integrity is perhaps enough. Such beliefs, he argues, can be a powerful force for change: “The survival of a lingua franca is always a matter of confidence and ideology as much as reasoned calculation.”

Before Ostler’s own ideology—entailing a fanciful technological determinism—takes hold of his argument, The Last Lingua Franca is wide-ranging and insightful. He is on firm ground when he uses historical examples to question the future of English as a global language. He shows repeatedly how governments abolish even well-established lingua francas “at the stroke of a pen” for ideological reasons. An especially neat case is the relegation of Persian both in India under British rule and in Central Asia after the Russian Revolution. For the British, this was as simple as changing the language of the courts, on the principle that “justice should be comprehensible to those being judged” and not just to the Persian-speaking elite. In the new Soviet republics of Central Asia, the lingua franca was edged out on the grounds of ethno-linguistic self-determination. The revolutionary government drew up the borders of Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, and Kyrgyzstan according to the language spoken in each region, and raised literacy in these from less than 10 percent under Tsarist rule to almost 100 percent by 1959, at the expense of Persian.