Are modern chuch Latin and classical Latin different languages?

Question

From a (probably now-deleted comment) elsewhere on SE:

[Church Latin and Classical Latin] are more or less the same languages. Some new words were added and the pronunciation changed over the years, but it is the same Latin language.

I must admit to not being an expert in linguistics, Latin, or the history of Latin, but I find it hard to believe that a language spoken today can be the same language as one spoken in the 1st century. Furthermore, I see the two assumed to be different (Are there any active Classical Latin users nowadays?) in many ways, even down to having separate wikipedia pages.

Are modern church Latin and classical Latin considered to be the same language? What word describes their relationship (dialect, ancestor, etc.)?

Answer 1

In linguistics, language-relatedness is not a well worked-out science with a clear taxonomy of relations (such as "language" vs. "dialect"), so this is one of those "it depends on how you define..." questions. If two language forms are not mutually intelligible to monolingual speakers, we generally say that they are different languages. Since there are no first-language speakers of any form of Latin, the mutual-intelligibility test is not clearly performable. Even if you draw only on "really good" speakers of Latin, it is highly unlikely that anyone learns one form of Latin without also learning a reasonable amount of the other form – there won't be any monolingual speakers, even if one person was trained mostly in Church Latin vs. Classical Latin.

Outside of linguistics and even inside linguistics, it is widely thought that English (as currently spoken) is one language. Yet various forms of English are on the borders of mutual unintelligibility, at least at the level that Spanish and Portuguese, or Danish and Norwegian are.

Mutual intelligibility is, as you would expect, not a clear yes/no distinction. It would be interesting to take sets of related languages and do controlled experiments with speakers so that we could say with some degree of precision how easily monolingual speakers of A can understand speakers of B.

Answer 2

Church Latin and Classical Latin were quite different phonologically. Classical Latin was syllable-timed and had vowel length and predictable stress; Church (i.e, Medieval) Latin was stress-timed and had lost vowel length and stress was (therefore) unpredictable. My guess is that if a fluent speaker of one and a fluent speaker of the other had to discuss something they both knew about, they would each think the other's accent barbarous, but they would eventually be able to understand one another.

The issue is native speakers; there were many fluent speakers of one dialect or another of Medieval Latin over its 1500 or so years, but no native speakers born in a speech community. For the first 15 centuries of the Christian Era, anyone in Europe who read or wrote anything -- with very few exceptions -- read and wrote in Latin, whatever language they spoke natively. Thus, all fluent Latin speakers were literate, having learned the language in order to be able to read and write. This constituted a very small (but very important) proportion of the population. However, this is the case for Classical Latin as well.

By the time of J. Caesar, the language spoken in the streets of Rome was not the same as Classical Latin, since it was Vulgar Latin -- a quite different language, and busy turning into all the Romance languages (Modern Italian is basically the Tuscan dialect of Vulgar Latin with two millennia of age on it). The first thing that happened was a lot of sound changes, leading to a total restructuring of the grammar -- no cases and only two genders, for instance. So the fluent speakers of Classical Latin from early Imperial times were not native speakers of it, either. Diglossia was a prominent feature of European language communities, and still is in many places.

So, since the language was identical when written for 1500 years and could be spoken by many at any time (it was necessary for any serious work), though the pronunciations and word meanings changed, as necessary, when the cultures did. I'd say they were the same language, as much the same as Mexican Spanish and Peninsular Spanish, say.