free variation in pronunciation

[Laurence Horn]

At 8:54 AM -0400 4/3/01, Dennis R. Preston wrote:
>Lynne hits the nail on the head here. I take the two forms - two
>meanings (in the broad sense) to be a pretty good general account, so
>much so that I would want to examine claims to the contrary (and free
>variation is always such a claim) very carefully.

Does anyone have an early cite on who said this first?  Bolinger, at
various places, argued for a position along these lines (including
the precept that there's no true free variation), and I've cited this
accordingly as Bolinger's Law, but I suspect he wasn't the first, and
that someone like Hermann Paul may have expressed a similar
sentiment.  Can anyone pin this down a bit more?

larry