Here's Arrington's summation of Craig's reply:
Craig first shows a picture of a dilapidated old East German Trabant, one of the worst cars ever made. He then shows a picture of a shiny new Mercedes E Class. Then he makes the following argument.Ayala makes the mistake of thinking that intelligent design theory requires that the designer be the God of Christianity (which many, including me, believe it happens to be), but that's a theological supposition. To debate the scientific value of intelligent design theory by importing theological assumptions is neither germane nor helpful.
Conclusion: Known designs exhibit various degrees of optimality. Therefore, there is simply no reason to restrict design inferences only to maximally optimal designs. If a structure meets Dembski’s criteria for inferring design, that inference is not refuted by the mere possibility that the structure could have been better designed.
- The Trabant is obviously designed.
- The Trabant design is obviously sub-optimal.
- Therefore, the fact that a design is sub-optimal does not invalidate the design inference.
Craig then shows a picture of a medieval torture device and makes the following argument.
Conclusion: The design inference says absolutely nothing about the moral qualities of the designer.
- The torture device is obviously designed.
- The designer was obviously not good.
- Therefore, the possibility that the designer is not good does not preclude a design inference.
Intelligent design advocates, unlike creationists, argue that the case for design should be made scientifically and philosophically. It's ironic that it's the Darwinists who insist on turning the debate into a theological exercise. IDers want to limit the discussion to the scientific and philosophical evidence for the existence of a designer and leave the identity and nature of that designer to the theologians. Those are not matters upon which ID takes any formal position.
Here's Craig delivering his argument against Ayala:
It might be wondered what the value of the ID argument is if it doesn't demonstrate the existence of the God of Christianity. The answer, it seems to me, is that to the extent that intelligent design makes belief in a designer compelling, to that extent the strongest alternative to theism, materialism, is shown to be false. Once someone is persuaded that the universe is the product of an intelligent mind and not just some accident of impersonal nature then he has taken a giant step toward theism and away from naturalistic materialism.