Great column from Uriah Kriegel on scientific theories and the Intelligent Design debate. Here’s the point:
Popper concluded that the mark of true science was falsifiability: a theory is genuinely scientific only if it’s possible in principle to refute it. This may sound paradoxical, since science is about seeking truth, not falsehood. But Popper showed that it was precisely the willingness to be proven false, the critical mindset of being open to the possibility that you’re wrong, that makes for progress toward truth.
Sounds like a good line of demarcation. If you have a theory that could never be proven false (e.g., Intelligent Design) then what’s the point in debating it.