When did Atlantis start to mean “undersea civilization”, not “totally destroyed, extinct civilization”?
Stories of the island sinking were already in Plato’s dialogues, so sometime before then…
Plato didn’t talk about a civilization of merfolk did he?
Atlantis started being a “hidden civilization still existing” at the beginning of the 20th century, although in most it was seen as being in the middle of the Sahara, or in South America, on some lost island, or elsewhere.
As far as I know, the first “sunken empire of Atlantis still alive” was David M. Parry’s 1906 The Scarlet Empire, in which Atlantis is under a dome at the bottom of the ocean. I have to admit that I’ve never read it.
Here’s an essay I wrote about Atlantis, with special emphasis on the George Pal movie:
Thank you, that essay is a wonder.
Thanks
Wait, there’s a classic formative work of science fiction that CalMeacham hasn’t read? Next you’ll be telling me that Santa isn’t real!
Plato’s use of Antlantis was clearly allegorical and in no way indicated an earlier myth or oral tradition.
Ignatius Donnelly’s book precended it by 24 years, though he didn’t suppose it was “still alive,” he was the first to mount the hypothesis that Atlantis was a real place and a lost super-advanced civilization. Atlantis really begins with Donnelly, not Plato (at least as the OP puts it). Edit: I’ve since followed your link and see you write extensively about this book.
Donnelly was also the first to suggest Shakespeare didn’t write Shakespeare’s plays. He was a prolific crackpot and theorist.
I guess I’ll add that my understanding of the Atlantis myth is pseudohistorical advanced civilization that has been destroyed at the bottom of the ocean; I have seen fantasy/sci-fi treatments where Atlantis is still there under a dome or whatever but it feels different to me where people actually believe the advance/destroyed civilization but know the “Atlantis still there under a dome” is pure make believe. Don’t mean to split hairs, I just haven’t encountered anyone who believes Atlantis is there but have known people who sort of believed in Atlantis, the same kinds of people who believe aliens helped build the pyramids and “know” ghosts are real and so forth.
But Donnelly never said that Atlantis was an inhabited underwater city, which is the reason I brought that up (to answer the OP’s question). As you see from my essay, there’s a LOT about Donnelly’s book in it, including its central role in raising the modern interpretation of Atlantis (and the way that this is absent from, for instance, Jules Verne’s work).
Actually, Shakespeare’s authorship had been questioned by quite a few writers, most notably Delia Bacon, for several decades before Donnelly wrote on the subject. Not that this makes him any less of a crackpot.
It’s interesting that Atlantis being advanced meant that they were advanced in technology doesn’t seem to arise until modern times.
I guess in the old days “advanced” meant things like being learned, having a well developed religion, etc.
By the 1800s, the effect of new technology on the rapid progress of civilization became apparent.
I pulled out my copy of George Pal’s Atlantis, the Lost Continent over the weekend and watched it again. It’s the same wonderful mixture of pretty good and really awful stuff I remember, and I can’t help wishing it was a lotbetter. as it is, I’ve never been satisfied with any movie or novel about Atlantis. One of these days somebody ought to give it another shot.
One of the problems is that none of the people doing this have a sense of scale. They can’t cope with an entire continent. Heck, most of them would have trouble coping with a lost island. Most of what is done could be satisfied by simply having a lost City. And they often don’t have a coherent idea of what Atlantis really is, and what its history was, and why or how it “sank”. I think too much Atlantis fiction coasts along on the romance of a lost, probably high-tech civilization without asking the question about why someone with high tech either couldn’t sustain themselves, or move somewhere else. I may have to write this one myself.
Not Atlantis, but cf. “At the Mountains of Madness” 
thanks. read it many times, including two different annotated versions.
I’ve read lost of “Lost World” stories But I expect something different from an Atlantis yarn.
No, Plato, that well known liar, invented Atlantis. And in fact, it wasn’t supposed to be taken as fact, it was a parable.
Atlantis was Athens, and it was supposed to tell them not to be so arrogant.
If you want to tell arrogant people not to be so arrogant, maybe a parable isn’t quite direct enough.
Hemlock is sooo bitter, not tasty at all.
Not to get too far off track, but the collapse of the Old Ones’ civilization was explained by the revolt of the shoggoths, no? And the the culture of the Old Ones themselves had already become degenerate by this point, at least according to the interpretation of Lovecraft’s protagonist.