In science it often happens that scientists
say, 'You know that's a really good
argument; my position is mistaken,' and
then they actually change their minds and
you never hear that old view from them
again. They really do it. It doesn't happen
as often as it should, because scientists
are human and change is sometimes
painful. But it happens every day. I cannot
recall the last time something like that
happened in politics or religion. [Carl
Sagan, 1987 CSICOP keynote address]

Ciao,
the monkeywrench