I am rather excited by various developments which seem to show that Latin may be making a comeback: the Living Latin movement, for example, and some recent publications of Medieval and Neo-Latin texts. It seems possible to me that some momentum may be accumulating.
"Latin is a language without a country. It is not the native language of any country. That is why it is doomed."
It was a language without a country when the Western Roman Empire fell in AD 476, and for well over a thousand years after that it remained the international language of western Europe. It was not a global language as English is today, and I don't happen to know whether or not the reach of Latin was greater than that of Arabic or Chinese, but within western Europe, it was universal.
In European universities, from Finland to Portugal, to Lima, Peru, where St Mark's University was officially established in 1551, lectures were given, discussions were held, and examinations, oral and written, in Latin. Latin was the language of mathematics and physics, of botany, chemistry, geography, medicine. Newton published his Principia, in 1728, in Latin. Spinoza published a few minor early works in Dutch, and then all of his major works were in Latin.
Descartes and Leibniz each published about half in Latin and half in French. Francis Bacon and Thomas Hobbes wrote mostly in Latin. Milton wrote in English, Italian, Latin and Greek, the show-off! But these were all 17th- and 18th-century figures, coming at the end of the period of Latin's dominance in Europe. Before the year 1600, although there certainly was a large amount of vernacular literature, exactly none of it could have been considered academic. Latin had no country of its own, that's true, but it did have communities, including the academic community. Students and professors traveled all over Europe and employed the same language wherever they went. It was expected that a professor would teach in several countries over the course of his career, in part to ensure that ideas circulated internationally.
Latin was the language of royalty and high aristocracy, and of international diplomacy. It was not always expected that every single king and queen could speak brilliantly and spontaneously in Latin, but the advantages of being able to do so were large and obvious.
In the 16th and 17th centuries, military generals, colonels and majors came from the aristocracy, and they traveled internationally, working sometimes for this country, sometimes for another. Although in this case it had less to do with the spread of ideas than with the mercenary officers seeking the most advantageous positions. And all over Europe, battlefield commands were shouted out in Latin.
Latin was the international European language of shipping and commerce. Christopher Columbus did not attend a university, but he did learn Latin, in order to be a ship's captain traveling internationally, and also in order to read works about the Earth's geography which were all either originally written in Latin or translated into Latin from Greek.
So you see, although Latin did not have a country, for over a thousand years it still had some very important uses. And I didn't even mention the Middle Ages, or theology! It may have been no-one's first language -- or very few people's first language -- but it was very many people's second language. The time in which Latin has declined is still a very short time compared to the time when it flourished.
Anyway, when I said yesterday that I was very excited because I thought Latin might be about to make a very big comeback, I was not thinking about it replacing English as the world language numero uno (see what I did there? never mind). I was merely expressing the hope, shared by some others, that Latin may be reviving somewhat from the low point in popularity it has recently reached. At the very least, perhaps more people will resume studying several thousand years' worth of the history of hundreds of millions of people in the language in which it was written.