The word-order story of ancient compounds seen in Plain-language explainer 3, we check here in Orikuchi Shinobu’s own paper. We also read another topic from the same paper — the change in a word’s form when it forms a compound. (The English renderings of the quotations below are ToL translations.)

Hashi wasn’t only level things

First, the story of hashidate (a ladder). Orikuchi writes:

昔は渡る或は渡すと言ふ様な場合、即、此方から彼方へと二つの場所を繋ぐものは総てはしで、垂直的のものをもはしと言うたのである。

(In old times, in cases like crossing or spanning — that is, anything joining two places, from here to there — was called hashi, and vertical things too were called hashi.)

Taking the writing “立橋” in the Harima Fudoki as a clue, Orikuchi thinks that the word hashi was not limited to level bridges.

Kataoka isn’t the name of a hill

Next, kataoka (傍丘).

傍丘は丘の名ではなく、丘の傍といふ事で、今ならば、恐らく不安定を感じる筈の丘傍と同じ意味の言葉であつた。

(Kataoka is not the name of a hill but means “the side of a hill,” a word with the same meaning as okakata (丘傍), which today we would probably find unsettling.)

Note the phrase “which today we would find unsettling.” Orikuchi himself admits that to the language sense of modern people, “okakata” sounds more natural. Having granted that, he says that people of old differed from people of today in their consciousness of grammar.

Sake becomes saka

Now comes the paper’s other center. In Japanese there are many examples in which, when forming a compound, the form of the earlier word differs from its independent form. Orikuchi gives:

When a noun with an e-column sound enters a compound, it changes to an a-column sound. For example, sake (“rice wine”) + taru (“barrel”) becomes sakadaru; kaze (“wind”) + borōshi becomes kazaboroshi; suge (“sedge”) + kasa (“hat”) becomes sugagasa.

此は単なる音韻変化ではないのであつて、熟語を作る場合の語根の屈折が、自然に機械的に整理せられる様になつて取つて来た規約である。

(This is not mere sound change; it is a convention that came about when the inflection of a word root in forming compounds came to be sorted naturally and mechanically.)

When sake-daru becomes sakadaru, we tend to vaguely think “the sound changed.” Orikuchi says that is not enough. There was a definite rule that when forming a compound, the earlier word changes to a fixed form.

Orikuchi also gives other examples.

Behind these changes, Orikuchi thought, there may have been a property of word roots being close to u-column sounds. That part, however, is Orikuchi’s conjecture.

Independent form → form inside a compound sake → saka + daru kaze → kaza + boroshi suge → suga + gasa ki → ko / ku + gane hi (fire) → ho Orikuchi Shinobu: "not mere sound change" — a rule for forming compounds
Examples of a word changing form inside compounds. Diagram: ToL

Orikuchi draws the line himself

One more thing to note in this paper is that Orikuchi himself states the limits of conjecture. In the latter half, where he discusses how verb conjugation came about, he writes:

言葉の研究は、ある程度以上に考へを進めれば、勢ひ推測になるのであるから、或程度に停めて置かなければならないのである。

(Word research, if thought carried beyond a certain point, inevitably becomes conjecture, and so must be stopped at some point.)

True to these words, Orikuchi writes plainly, on the origin of verbs, “in fact, the origin of verbs is unknown.” Even so, he says that considering the era when word roots worked more freely would shed “a faint light” on the emergence of verbs and predicates, and thus argues by separating what is known from the range of conjecture.

What this paper shows

In this paper, Orikuchi tried to show that the old forms of Japanese had rules of compounding differing from the sense of us today. That he pointed out traces of it inside very familiar words like sakadaru shows the keenness of Orikuchi’s observation. On the other hand, as Orikuchi himself says, the explanation beyond that contains conjecture. How that is treated, we sort out in the verdict article.

Summary

PointDetail
HashiOnce anything joining two places, including a vertical ladder
KataokaNot the name of a hill but “the side of a hill”; Orikuchi grants that okakata feels more natural to moderns
Change of formsake → saka, kaze → kaza, suge → suga, ki → ko/ku, hi → ho: a rule, “not mere sound change”
Orikuchi’s conjectureThat word roots are close to u-column sounds; but this is conjecture
Orikuchi’s stanceStates the limits: “beyond a certain point, it inevitably becomes conjecture”

In a nutshell — in familiar words like sakadaru, Orikuchi Shinobu saw an old rule of compounding. And he drew the line himself between what is known and what is conjecture.