Granny Smith, Honeycrisp, Red Delicious? All apples, wildly different, all common. Even within the more commercially available variants there are significant differences: https://www.jessicagavin.com/types-of-apples/
> "Apple" is a generic name, that does not actually really express anything particularly specific.
...
> "apple" as an idea doesn't really express anything concrete without lots more context.
I understand where you're coming from and appreciate the nuance, but can't help to feel that you've moved the goalposts from the earlier:
> There are no "ideas" independent of expression.
I never meant to claim that ideas have to be concrete or specific, if anything, the best thing about an idea is that it is not any of those.
And it's clear to me that you did perfectly understand what I meant by:
> "apple", "manzana", "pomme", "mela", "maçã"
as you then said "isn't even a fruit", so I was able to effectively communicate to you the abstract idea of a particular type of fruit. Communication of ideas does work to promote coordination of actions (in this case a comment thread on "the same topic"), and while flawed and fuzzy, I don't see how it could function if there were no ideas independent of expression.
Eating apple, cooking apple, cider apple, pig feed?
Granny Smith, Honeycrisp, Red Delicious? All apples, wildly different, all common. Even within the more commercially available variants there are significant differences: https://www.jessicagavin.com/types-of-apples/
Heck, just for cooking apples there are huge number of different varieties: https://en.wikipedia.org/wiki/Cooking_apple
Yea, "apple" as an idea doesn't really express anything concrete without lots more context.
And without more context, Apple may even mean something that isn't even a fruit, but still popular: www.apple.com