Jörg Rhiemeier <[log in to unmask]> writes:
> It indeed reminds me remotely of the degree of volition system
> I have in Old Albic, but only remotely.  What regards fluid-S
> languages, what the term means is the following: an intransitive
> subject is marked like a transitive subject if the verb denotes
> an action performed by the subject (as in `The man runs'), but
> like a transitive object if it is not (as in `The stone falls').
> Some verbs allow either marking depending on whether the subject
> acts out of itself (yes in `My brother arrived yesterday',
> no in `Your letter arrived yesterday').

Interesting.  And when looking at the causes,
   'My brother arrived yesterday'

is reflexive:
   'Yesterday, my brother's arrival was caused by *himself*'

   'Your letter arrived yesterday'

lacks the reflexiveness:
   'Yesterday, your letter's arrival was caused.'

Of course, this is linked to the difference in volition, but the
reflexiveness is funny, I think.  (And in a language with a medium
voice or similar means, you could have an 'appearance' character of
the verb 'to arrive': 'the letter arrived' would lack a cause, so it'd
mean: 'the letter appeared in the postbox' :-))).

It let's me think about how to implement reflexiveness in my current
project S11, where only unary verbs exist, so 'reflexive' would always
be a long distance concept.