Historical question on "open"

[Douglas G. Wilson]

>         A visiting scholar from Korea today wondered why we use
>"open" rather than "opened" in a sentence such as the following:
>
>         The door is open.
>         The door is closed.
>
>whereas we use the past participle "closed" in the parallel sentence.
>German and Spanish both use past participles (geo:ffnet, abierto).
>Does anyone happen to know the story of how we came to have just "open"
>in this context?

Maybe the question should be why we use "closed" rather than a "pure
adjective" such as "close" ....

A few remarks, which may not fully answer either question. No doubt some
expert can correct me if necessary.

(1) We also have the adjective/participle "opened" = "open". I see nothing
impossible about "He stood beside the opened window" or "I put a doorstop
against the opened door".

(2) We also have the adjective "close" = "closed". It seems archaic to me.
My OED shows examples such as "close hatch" = "closed hatch", "close
carriage" = "closed carriage". I would speculate that such sentences as
"The door is close" = "The door is closed" have been avoided because of
ambiguity.

(3) German also uses the adjective "offen" = "open". I don't know of a
conventional "pure adjective" form of "geschlossen", however.

(4) "Open" itself looks like the past participle of a Germanic strong verb
cognate with "auf" (or "up") -- as noted in the OED. Cf. German "die Tür
aufmachen" or so, = "[to] open the door" (I think some English dialects
also include "[to] make the door up/to" = "[to] open/close the door").

(5) Semantically ... ["door" is ambiguous, meaning either the doorway
(opening) or the slab which occludes it, so I'll use "passageway"] ... A
passageway which is closed is necessarily a passageway which has been (has
become) closed, but a passageway which is open is not necessarily a
passageway which undergone an opening: it may have always been open
(whereas one can assert that a passageway which has never been open is no
passageway at all). An analogous contrast: "The road is clear" (with "pure
adjective") versus "The road is blocked" (with participle).

-- Doug Wilson