I found a comment by CLADIVS (Claudius) in Good and bad reasons for rejecting ID that is worth highlighting.
But without a testable explanation, ID remains in the realm of metaphysics, philosophy or religion, not science.
ID may not be science, but that does not mean automatically it is religion.
If I have a coin in a box and shake it, look at it at 11:27 AM on 6/26/13 and determine it is heads. You have no way of scientifically verifying the claim via a process of repeated experiments 10 years from now. You’ll just have to take my word for it.
The fact that a true claim about the history of the physical universe is not accessible to science does not make the claim automatically a religious claim. It might be true in the physical sense.
Notions of good and evil etc. are definitely in the realm of philosophy, claims about physical universe are not necessarily religious just because they are inaccessible to science.
If by science one demands that the mechanism is repeatable and observable, then ID is not science, but such a definition is a two-edged sword. By such a definition of science, there are a lot of scientific theories based mostly on inference that would be rejected as science. Some examples are given in: What qualifies as science in the wonderful world of Disney.
By such a strict definition of science in terms of experiments and observables, evolutionary biology is not science either:
Ernst Mayr (as quoted by McHugh):
Evolutionary biology, in contrast with physics and chemistry, is a historical science…[where] Laws and experiments are inappropriate…
Instead one constructs a … narrative
I’m ambivalent to the arguments whether ID is science or not since it depends one’s definition of science. The question at hand is its reasonableness versus the alternatives. But supposing for the sake of argument it is not science, it does not automatically make it a religious, metaphysical, or philosophical idea.
I’ve suggested, on scientific grounds alone, an Intelligent Designer may be inferred to exist. See: Quantum Enigma of Consciousness and the Identity of the Designer.
And strictly speaking, ID-sympathetic theories might be verifiable one day, and hence they could qualify as science in the strict sense. If after you die and find yourself facing Almighty God on judgment day, then by the standards of science, ID is verifiable because then you would have been brought back to life and are facing the Intelligent Designer himself. Of course, if ID is false and there is no Intelligent Designer of the universe and life, you have few worries that you’ll ever face Almighty God.
But, imho, there is the chance everyone reading these discussions might see the Intelligent Designer one day, and hence these discussions have merit independent of whether one views ID as science or not. As an aside, the father of the concept of expectation values, Blaise Pascal, had something to say on the rationality of wagering on the existence of the Intelligent Designer based on your presumed distribution of the possibility of his existence…See: Pascal’s Wager. For me, I’m not wagering Darwin, Dawkins nor Dennett are right. That’s a bad bet in my book….
In sum, even supposing ID is not science, it does not automatically mean it is philosophy, religion, or metaphysics since it is making a claim about physical events rather than esoteric claims about what is good and evil.