accusative and ergative languages

[Jens Elmegaard Rasmussen]

On Thu, 10 Jun 1999, Patrick C. Ryan wrote:

> [...] I do continue to believe that any language which is
> presently or has been accusative must have gone through an ergative stage
> sometime prior to that in its development.

Could you give us five examples of languages for which this sequence of
events is known with certainty? Should be easy if it applies to all.

> [...] To try to understand ergative constructions from
> passive inflections developed in languages in accusative stages seems to me
> to be potentially misleading.

"Potentially" perhaps, but in some cases certainly in accordance with the
truth of a documented development. Why it that so often disregarded in
typology-based solutions?

Jens