It's not? What are SAT scores, school grades, entrance exams for the civil service, election results, income etc.?
I would say that these are all ways for society to quantify merit.
Did you mean perfectly accurately?
> literally every government that has ever existed would call itself a meritocracy.
Nope. Most governments used to call themselves monarchies and would have bristled at the idea that they'd have to somehow demonstrate merit to justify their power. Their power was justified by heredity, and in fact, I'd think that if you suggested that they needed to do demonstrate their merit, you might end up short a head.
> The book
Yep. Have to admit I didn't read it, but I did read what the author wrote:
"It is good sense to appoint individual people to jobs on their merit."
What he objects to is the following:
"It is the opposite [of good] when those who are judged to have merit of a particular kind harden into a new social class without room in it for others."
So merit-based selection: good. Ossified class system: bad. I think Trump, May and Johnson are ample evidence that we leave plenty of room for the incompetent to get a chance at the reins, even if we generally try to organize ourselves by merit.
And so exactly the fact that we can't quantify merit with perfect accuracy, and have multiple domains, helps us avoid the problems Young mentions, though here as elsewhere we aren't at all perfect.