ID theory makes 1 claim - design exists and can be detected by scientific investigation, conclusions reached by calculating the probabilities.
The rest is philosophy.
You have the matter flipped and standing on its head. Design is apparent without scientific investigation.
Science does not detect design. The fact that science is possible “presupposes” the existence of design. Likewise, science does not prove that nature is intelligible. Science is possible only because nature is intelligible. We do not need science to tell us the world is intelligible. And neither can science tell us “why” the world is intelligible.
This is where ID theory fatally confuses the “special experience” of the natural sciences with philosophical inference. That nature exhibits design is in itself a philosophical inference.
If science was required or needed to “prove” design, then one will have to explain how pre-scientific cultures inferred design in the world.
Natural biological systems or organisms can be immensely complicated, and to a degree that boggles the mind. However, strictly scientific descriptions of the complexity adds nothing to the bare fact of design.
Even the simplest of organisms exhibits “design”, a fact which is a philosophical inference. “Specified complexity” adds nothing to that initial philosophical observation. One can assume that specified complexity suggests that the structure could not have come about by Darwinian means, but it is not a scientific judgment to assert that the structure in question is designed. Even the simplest of organisms exhibits “design”.
ID theory has these matters inexorably confused, as Father Oakes pointed out.
“Primarily that ID advocates seem regularly to confuse finality with design. Now because people only design things for a purpose, the two concepts are too often conflated. But they are different.” And…
“I also object to the way the ID Movement conflates the Thomistic distinction between primary and secondary causality. The advocates of this movement claim that if it can be proved scientifically that God must intervene on occasion to get various species up and running, then this will throw the atheist Darwinians into a panicked rout.”
Buffalo’s objection that things are designed for a purpose misses the point entirely. Things are in fact designed for a purpose, but purpose and design are not the same thing.
The act of creating is not identical with the thing created, and neither is the “purpose” for which it was created identical with the thing created.
However, I don’t expect ID theorists to catch any of this, which is why I don’t spend much time on the topic. For much the same reasons, Thomist philosophers generally refuse to have much to do with ID theory.