It turns out that it’s also impossible to determine precisely where one “language” leaves off and another begins.

An example is certain languages—um, dialects?—in Ethiopia. According to data from Sharon Rose of the University of California, San Diego, speakers of Soddo say, for “he thatched a roof,” kəddənəm. (The upside-down e is pronounced a lot like the oo in foot.) Not far away, people speaking Muher say it starting with kh instead of k: khəddənəm. A further ways distant, people who speak what they call Ezha say it with an r in the place of the n: khəddərəm. In Gyeto, the same word is khətərə. Then in Endegen they start with an h instead of a kh: həttərə. Now, where we started and where we finished look like what one might call different languages: Soddo’s kəddənəm and Endegen’s həttərə seem about as distinct as French’s dimanche and Italian’s domenica for Sunday. But in between Soddo and Endegen are several other stages—I only gave a few of them—that each differ from the previous one by just a little change, such that the speakers can converse. If those stages are “dialects,” what are they “dialects” of? Both Soddo and Endegen over on the ends?

All of them are simply dialects—even though the ones on the ends are not mutually intelligible and don’t feel like the same “language” to their speakers. Speech worked this way from village to village across Western Europe until recently, when unwritten, rural dialects started steadily disappearing. People now know this area as home to a few “languages” like Portuguese, Spanish, French, and Italian, but on the ground there once was basically a smudge of countless Romance “dialects” shading gradually into one another from Portugal to Italy. In each nation, the serendipities of history chose one “dialect” as a standard and enshrined it on the page, but in real life, the situation was much like in Ethiopia. There are hints of this history today; in Catalan in Spain, “key” is clau; to the north, in Occitan, it’s clau as well; but then a little further north, in obscure rural varieties called Franco-Provençal, it’s clâ; in the Romansh of the Swiss mountains it’s clav; in the northern Italian variety Piedmontese it’s ciav (pronounced “chahv,”); and then in what’s known as standard Italian it’s chiave (pronounced “KYAH-vay”).

The idea of distinguishing “languages” from “dialects” is of no logical use here. As often as not, it’s more that speech is a little different from place to place, such that a person can get along speaking when in the town a few valleys over; one starts having trouble the further away he gets; and after a traveling a certain distance can no longer understand a thing anyone is saying.

The only thing that can save an attempt to impose a formal definition on the terms “language” and “dialect” now is perhaps to be found in popular usage, which suggests that languages are written and standardized and have a literature, while dialects are oral, without codified rules, and have no literature. Now, a typical objection to using literature as the dividing line is that there is oral literature—the Iliad and the Odyssey likely originated as memorized poems. But even allowing that memories can only retain so much, and that perhaps it is legitimate to distinguish what Greek bards knew from, say, Russian’s written literature, there’s another problem.