Books are a strange blessing.

[Beeesneees]

@Eugene2114

Where do you spot the hint making you conclude some books defy the description? In such a short sentence, out of context?..

Sorry, I can’t explain it clearer than I have. Just because all books aren’t good, doesn’t mean that some of them aren’t good. It’s in the emphasis, and it is more philosophical than grammatical in nature, you are right. The whole point is that there is no context to explain which version is correct.

As I’ve also said, ambiguity would be avoided because in certain cases the statement would not be used as written in this thread.

“All the released are not guilty” = some of them should be brought back in jail?..

Yes, possibly. Some of them might be guilty. Again, the usual form would then be
Some of the released are (not) guilty.

[Beeesneees]

@Anglophile

For a standalone sentence to carry the same idea, the use of ‘Not all those released are (really) innocent’ will be better.

‘Some of the released are guilty’
would get straight to the point.

[Anglophile]

Yes, it is acceptable, too.