Live all you can: It’s a mistake not to.
Is it conceivable that people should never speak an audible language, but should nevertheless talk to themselves inwardly, in the imagination?
"Each other" WOULD make more sense! (And would save us all a lot of grief.)
I think he means both to themselves and to each other....
After having read Until Further Notice I Am Alive, by Tom Lubbock, which I read after reading The Iceberg, by Marion Coutts, which you had mentioned recently, I understood that Tom Lubbock expressed amazement that as his ability to speak or read was diminishing because of his brain tumor, his ability to talk to himself inwardly was as rich as ever. At least that it what I understood him to be saying. Have you read his book? He talks about believing in "the goodness of the world." An astonishing book. Interesting that you posted this, because when I saw that quote by Wittgenstein on another blog, I interpreted "talking to themselves" as meaning "talking to each other." Now I see a distinction. A fine distinction. A fascinating quote. (-: