A Son of the Rock

I heard Kirsty Wark use the phrase “all is not lost” on The Book Quiz this week.
Oh, Kirsty.

You see: all is lost (semantically) if the phrase is taken to mean “there’s some hope, still” because what all is not lost actually means is everything is exactly as it ought to be and therefore there isn’t and – never has been – a problem.
“All isn’t lost” can only mean nothing is lost; hence everything is fine. (Either that or all does not mean all.)

The phrase that really does mean “there’s some hope, still” is slightly different and would more accurately read, “not all is lost.”

Consider an equivalent construction to “all is not lost;” the statement “all policemen are not six feet tall.”
This means no policeman can be six feet tall, because all are not that height; hence every policeman must be some other height than six feet.

Whereas, to say “not all policemen are six feet tall” means that some- perhaps even most – may be six feet tall but others can be of a different height.

It is “not all is lost” that means some is lost but not that everything is. Not all.

Hope that’s cleared things up.