Is 「なので」actually a short-form for「それなので」?

Question

In Tae Kim's Guide there is a conversation that goes like this:

Tom: 時間がなかった。

Mary: だからパーティーに行かなかったの？

I was wondering is 「だから」 actually a short-form of 「それだから」 ?

Similarly, in the sentence 「なので、友達に会う時間がない。」, is 「なので」 actually a short-form for 「それなので」 ?

I was thinking does the 「それ」in 「それだから」have anything to do with the 「それ」in this question. Does the 「それ」in「それだから」imply that the "thing" is not known by the speaker but by the listener?

Answer 1

This question is difficult to answer without a definition of what is and isn't a "short-form", but here are some thoughts.

なので and だから (and けれど, が, etc.) are in modern Japanese able to function as fully independent sentence-beginning lexemes. They are not "short forms" of そうなので etc. any more than 書いた is a "short form" of 書いたり/書いたる. (However, they are obviously etymologically related to clause-final usage of なので and だから, just as 書いた is etymologically related to 書いたり/書いたる.)

As evidence, consider that as discussed in comments in many cases it is not possible to substitute a "long form" without changing the implication somewhat. Here are some intuitive observations about my own idiolect (note that I am not a native speaker).

• それだからパーティーに行かなかったの？, そうだからパーティーに行かなかったの？, etc. are not at all equivalent to だからパーティーに行かなかったの？ Note that だから is a couple hundred years old and was sometimes written with kanji making it clear that it was not considered short for anything, e.g. 然から. (That's from a mid-19th century example in 日本国語大辞典.)
• Sentences beginning with が can always be rewritten だが or ですが, but again, not それだが or そうだが in most cases.
• なので strikes me as the least resistant to a そうなので rewrite -- but still pretty resistant, and more to the point, such rewrites sound awkward and unnatural even if technically allowed.

And here are some counterarguments to the above:

• First, the prescriptive argument: なので or が　have to imply something before them because なので and が can't appear independently. This is a "just because" sort of argument similar to "You have to use 'were' for the subjunctive case in English; 'If I was' is just plain wrong." I do not put much stock in this sort of thinking (although there are times when a certain strictly defined style is required, and this should not be ignored) but I include it for completeness. I do know if there is any prescriptive objection to だから or です.
• Second, the "invisible structure" argument: these words don't actually include a それ or a そう, but that at some level their use implies something equivalent to それ or そう in the structure, and therefore, the "full form" is "there" in some sense. I am not sure if any school of linguistic analysis would actually make such an argument in this case, but I include it as a possibility.