I would say yes, anything that follows the form of science we would call naturalistic. But that is terminological only. Consider the concept of energy or an electomagnetic field or a quantum state. We think of these things as naturalistic but they are pure inventions of the human mind. Just because we're so used to them doesn't make them real (phlogiston and aether come to mind as failed scientific inventions) but they are naturalistic.
Now I do not claim that it is impossible to construct a scientific theory of design. However I would say that, should some theory of design be wrestled into the necessary explanatory form, it will be a naturalistic theory. That would be a curious result, and I suspect that you will find it unsatisfying.
If we find that science is incapable of recognizing the "presence of engineering" when we know it's there, then it suggests that science in its present state, is not a reliable method for explaining biological observations.
Hmmm. It's the old "if it doesn't explain everything then it doesn't explain anything" ploy. Because Newton's theory of gravitation doesn't explain the observed precession of Mercury's orbit, it's not a reliable method of explaining gravitational phenomena. Right.
But that doesn't seem right, as we can often recognize the difference between naturalistic and man-made causes.
I think that's a little off topic; we're concerned with designed vs. not designed (and that's not the same thing as naturalistic).
Certainly we can, in certain limited domains, reliably infer human design. But how do we do it? Well, it's because of lots of experience. We "know" that these objects are intentionally created by people. But go outside these limited domains and the sense of human design becomes unreliable. AIDS is biowarfare against Africans doncha know. Trying to use this demonstrably unreliable sense outside of human design seems folly to me.
The key point is that Intelligent Design is a valid hypothesis.
No, the key point is that ID isn't a scientific theory. It isn't because it does not have the right form. If you IDists want it to be accepted as science, it is up to you to do the work to make it so.
Not really. But at the same time, if it turns out that science is manifestly incapable of giving a correct accounting of the origin of a given phenomenon (i.e., it cannot detect that somebody made it that way), it would obviously be an unreliable explanatory method for that class of phenomena. We could not trust a scientist who says "nobody made it," because the scientist by definition has no way to know that.
But again: I think that, as a general rule, science probably is capable of detecting the signature of intelligent agents on a given phenomena.
Certainly we can, in certain limited domains, reliably infer human design. But how do we do it? Well, it's because of lots of experience. We "know" that these objects are intentionally created by people. But go outside these limited domains and the sense of human design becomes unreliable. AIDS is biowarfare against Africans doncha know. Trying to use this demonstrably unreliable sense outside of human design seems folly to me.
Well, yes, but in rejecting a "design hypothesis" in biology, you're essentially making an argument from ignorance. But we know, for example, that humans do genetic engineering, and thus in some cases we know what to look for if we make a design hypothesis. There is no intrinsic barrier to gaining "lots of experience" in recognizing the hallmarks of design in biology. If that's the case, it would be folly for a scientist to reject a design hypothesis, especially in cases where know what to look for. Your example of "detecting biowarfare" is an excellent example: if confronted with that scenario wouldn't it be irresponsible for a scientist to reject a design hypothesis?