I also think a scientist should keep an open mind. There are some people,
however, who claim to believe that *anything* is possible. "Anything
the mind can concieve and the will can believe, can be achieved."
(paraphrase of Napoleon Hill, Goethe or someone.) No one really
*acts* this way though. Some claim to believe that it's possible to
walk through a wall but they never act that way.
This appeal to the will to power is pretty attractive and is a great
setup for a con job. Witness the "Star Wars" foolishness. No one can
*prove* that hundreds of orbiting HF laser battle stations are
impossible, that thousands of boosting ICBMs *can't* be picked off by
the 8-meter optical system needed. The X-ray laser idea *could* be
possible!
A really open mind should also admit the possibility that there are
*impossible* notions. We just don't know what they all are.