Unidirectional developments?

[Ron Kuzar]

Dear FunkNetters,
It is well known that certain processes in the history of language are
bidirectional: Affixes may degenerate into non-morphology or pronouns may
be cliticized and eventually morphologized. But are there processes that
are only unidirectional? I have in mind two issues:
1. Periodic style: languages with a narrative style that chains short
sentences into a linear sequence often develop a periodic style at a
later phase of their development. Does anybody know of a language that
had had periodic style and developed a chaining style?
2. Expression of feelings: some languages which express feelings by
placing the feeler in the dative (or another oblique) case <angers
me/freezes me/hurts to-me the head/burns to-me the soul/etc> develop later
into feeler as subject <I am angry/I am freezing/ I have a headache/I am
desperate/etc>. Does anybody know of languages that developed the other way?
Processes that seemed unidirectional to philologists in the nineteenth
century motivated a discourse that viewed language development as
teleological, resulting in the 'best language'. Today this kind of
writing would be simply ridiculed. However, if some processes are in fact
unidirectional, what sort of terms could account for this phenomenon,
other than 'betterment', 'refinement' etc. along some (what kind of) axis?
Can you think of other unidirectional processes?
Any bibliography?
Ron Kuzar
kuzar at research.haifa.ac.il