Does the nominalizer 〜の require the adnominal form before it? If yes, why?

Question

A while back I was trying to break down 〜なの, and this is what I decided on (with the help of some of Bart Mathias's posts on mailing lists). ---------- My hypothesis is that the nominalizer 〜の requires everything before it to be in adnominal form (usually meaning, 連体形{れんたいけい} for inflectable words). In the cases of 形容詞{けいようし} (-i adjectives) and 動詞{どうし} (verbs), the 連体形{れんたいけい} is of course just the 終止形{しゅうしけい}: - 形容詞{けいようし} (-i adj): 熱{あつ}いの - 動詞{どうし} (verb): 切{き}るの In the case of 形容動詞{けいようどうし} (-na adjectives), the 連体形{れんたいけい} is simply adding 〜な, which works out great: - 形容動詞{けいようどうし} (-na adj): 変{へん}なの And finally, in the case of 名詞{めいし} (nouns), although they are not inflectable, we can consider both 〜の (possessive) and 〜な as ways to make them "adnominal" (I guess 連体詞{れんたいし} is the right translation into Japanese): - 名詞{めいし} (noun): 車{くるま}なの ---------- To confirm this theory is actually true, I think the only avenue would be to look in historical texts to see if things like 大{おお}ききの, 死{し}ぬるの, or しずかなるの show up or not. Unfortunately, I am far from being able to do this myself, so I haven't been able to go confirm. If it does happen to be true, I wonder *why* the nominalizer 〜の would require things before it to be adnominal. Is の really acting so much like a noun? It seems to be doing so syntactically, but really not so much semantically (from my beginner perspective). The only time it seems to semantically act like a noun is with 形容詞{けいようし} (-i adj) where you can kind of translate it as "thing" into English. This is my theory, but I'd be happy to hear about a 国文法 explanation if there is one, or an analysis which looks at historical texts.

Answer 1

I cannot discuss your main issue, but the following expression is not acceptable for a native speaker:

切るの、車なの、大ききの、大きの、死ぬるの、静かなるの

Answer 2

I found two possible answers:

The first is that it comes from a contraction of "MONO," which then came to cover both abstract and concrete things.

The second is that it acts on its own to represent a concept.