Origin of ~なければ ならない


The expression ~なければ ならない if I learned correctly means "must not not do ..."
as in:

日本語を勉強しなければなりません。 You must not not learn Japanese. (i.e. you need to learn
Japanese)

However, taken on face value it doesn't really make sense. しなければなりません
translates into "if (you) don't do, doesn't become (what?)". The confusing
part is that a direct translation into _modern colloquial_ Chinese makes
sense: 你不学日语的话，不成 = "If you don't learn Japanese, not become" = "You must
learn Japanese".

This seems like a Japanese borrowing from a common Chinese phrase; 不...的话 acts
like ～なければ, and of course なる is sometimes written 成る. However, the expression
does not exist in Classical Chinese, which I presume Japanese borrowed the
most (including all the un-Mandarin-y readings). Classical Chinese would use
不可～. I'm suspecting this might be a Chinese loan from Japanese, just like how
不不不不 is a syntactical English loan of "no no no no" and not really parseable
(Chinese has no word for "no", only 不 = not = ～ない). Putting something like
"must not" in a verb at the end is very un-Chinesey. Modern Mandarin-based
Standard Chinese has also borrowed lots of 和製漢語 such as 民主, 共和国, 歌姫, 写真, カラオケ,
and pretty much all the vocabulary related to biology and political science,
curiously.

So when did this expression start in Japanese? Does any equivalent to ~なければ
ならない exist in, say, Classical Japanese or Old Japanese? If so, it'd probably
be the Chinese borrowing from Japanese, not the other way around.




One of the definitions of `なる` (`成る`) is to be completed (`完成する`), or to
succeed (`成功する`), and thus carries the implication of "good". Consequently,
`ならない` then means not completed; not successful; "it won't become (good)".
Consider in English, if you say "That won't do", it begs the question: won't
do _what_? But it has been ingrained in your mind to know that "that won't do"
= "that's no good".

So to break it down into parts, `〜なければ` means "if you don't 〜", and as we just
said, `ならない` by itself means "no good" or "that won't do", you get "That won't
do/be good if you don't 〜". Thus implying that you must do it.

This is why there are multiple ways to express having to do something. Instead
of `ならない`, you can substitute `いけない` or `だめ`, both of which also express "no
good"/"bad". And instead of `〜なければ`, you can substitute `〜なくては`. The
translation changes slightly from "If you don't 〜", to "Not doing 〜", but
gives the same overall semantics. Compare

>   * 全部食べなければならない → It's no good if you don't eat all of it
>   * 全部食べなくてはならない → Not eating all of it is/would be no good
>

So I know this doesn't exactly answer your question of _when_ this expression
came into Japanese, but you can more easily see how the structure makes sense.




One of the definitions of `なる` (`成る`) is to be completed (`完成する`), or to
succeed (`成功する`), and thus carries the implication of "good". Consequently,
`ならない` then means not completed; not successful; "it won't become (good)".
Consider in English, if you say "That won't do", it begs the question: won't
do _what_? But it has been ingrained in your mind to know that "that won't do"
= "that's no good".

So to break it down into parts, `〜なければ` means "if you don't 〜", and as we just
said, `ならない` by itself means "no good" or "that won't do", you get "That won't
do/be good if you don't 〜". Thus implying that you must do it.

This is why there are multiple ways to express having to do something. Instead
of `ならない`, you can substitute `いけない` or `だめ`, both of which also express "no
good"/"bad". And instead of `〜なければ`, you can substitute `〜なくては`. The
translation changes slightly from "If you don't 〜", to "Not doing 〜", but
gives the same overall semantics. Compare

>   * 全部食べなければならない → It's no good if you don't eat all of it
>   * 全部食べなくてはならない → Not eating all of it is/would be no good
>

So I know this doesn't exactly answer your question of _when_ this expression
came into Japanese, but you can more easily see how the structure makes sense.

