This entry was published at least two years ago (originally posted on April 27, 2005). Since that time the information may have become outdated or my beliefs may have changed (in general, assume a more open and liberal current viewpoint). A fuller disclaimer is available.
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
(via Atomic Playboy)