Re: German style orthography

It seems really strange to me that s is always voiced at the start of
words... how did this arise? I could understand it if (since I'm
assuming that originally german had no contrast between [s] and [z]) s
was always [z] intervocally, but.. I don't know, I'd just really like to
know how it became voiced at the start of all native german words.
 A similar funny thing is basque: the number of words that start with
voiced stops seems to vastly outnumber those that start with unvoiced
stops. And most of the ones I can think of that do begin with unvoiced
stops begin with k. I wonder why....