New use of "unless"?

[Laurence Horn]

At 3:40 PM -0800 1/22/01, Arnold Zwicky wrote:
>herb stahlke records an occurrence of
>  >"I can't eat it like that unless I have heartburn all night."
>
>i'm fairly sure i've heard "without" used this way in pennsylvania
>dutch country, but i don't think i've heard "unless".
>
This is interesting, because this "or else" use of "unless" is not so
much a new sense for the connective (vis-a-vis the majority usage)
but an extension of the majority usage, in somewhat the same way that
positive "anymore" extends the majority (negative polarity) "anymore"
by lopping off an arbitrary constraint on distribution.  So here,
compare

I can't eat 4-alarm chili without taking Alka-Seltzer.
I can't eat 4-alarm chili without getting heartburn.

%I can't eat 4-alarm chili without I take Alka-Seltzer.    (OK in MO,
PA., etc.)
%I can't eat 4-alarm chili without I get heartburn.           ( "
"     "       "     "  )

I can't eat 4-alarm chili unless I take Alka-Seltzer.
%I can't eat 4-alarm chili unless I get heartburn.              (OK
for Herb's speaker)

Actually, the last one will be OK for everyone if we could somehow
see getting heartburn all night as a means to allow one to eat the
chili, and even then the tense might be off.  The idea (if I may wax
speculative) is that the two sentences are on a par logically--if I
eat the chili, it inevitably follows that I (have to) take
Alka-Seltzer or that I get heartburn, as the case may be--but
"unless" for most of us, as distinct from "without", must be followed
by a "remedy" rather than simply a result.  Actually, that won't
generalize in the right way, but in any case there's a pragmatic
requirement for most of us on "unless" that can be waived for the
dialect or idiolect of Herb's speaker.

larry