The objections to the theory of Intelligent Design (ID) are wide-ranging, but they all have at least one common thread: Contradiction. That is, every argument offered by critics of ID ultimately lands them in the midst of astonishing contradictions. And as they attempt to wiggle free of the incongruity, they frequently end up making very good arguments in favor of ID.
For example, critics of ID love to claim that there's nothing scientific about the theory of ID. However, to claim that ID isn't scientific, the ID critic has to ignore the fact that scientists have been invoking intelligent design for centuries as they have discovered, investigated and analyzed messages carved in stone and other ancient artifacts around the world. Of course, intelligent humans were credited for these particular phenomena, but even before that conclusion was reached, an inference to intelligent authorship was made. The point is, either invoking intelligent causes is scientifically valid, or it's not. Scientists know better than to suggest that the Rosetta Stone was formed by blind, purposeless natural processes. And yet when some scientists look at DNA—a molecule which carries instructions for building a living organism and is sometimes referred to as "The Rosetta Stone of Life"—many scientists feel quite comfortable restricting themselves to only blind, purposeless natural processes.
We routinely attribute certain phenomena to intelligent causes, and when we do no one berates us for having invoked the supernatural. For example, as motorists enter the town of Bend, Oregon where I live, they are greeted by a large topiary alongside the highway. The shrubs are sculpted to spell the word "BEND." Who would dare attribute the message in those shrubs to blind, purposeless natural processes? Isn't it far more reasonable to attribute the creation of that topiary to an intelligent (landscape) designer? Why is it "unscientific" to do so?
Critics will quip that such examples only speak to human intelligence, which again places them in yet another contradiction. For an instant of time they pretend to believe that intelligence can only be manifest in humans, but they quickly betray that when they express their support for programs such as the Search for Extra-Terrestrial Intelligence (SETI), a program built upon the idea that intelligence is manifest in [non-human] beings and that if our radio telescopes intercept a radio signal transmitted by such beings, we will be able to determine that the signal had an intelligent source. When they pledge their support for SETI, critics of ID are admitting that intelligent authorship CAN BE detected using scientific methods.
The stark reality is that intelligence leaves behind certain hallmarks, and if there were no scientifically valid way to distinguish between a signal from an intelligent civilization and the ambient radio noise of deep space, then SETI could never have been organized. And if there is a scientific method for determining intelligent cause, then in the interest of objectivity, that method would have to be applicable to any kind of phenomenon, including biology. When biologists uncover the kind of evidence that, had it been received through a radio telescope, would have sent SETI fans into a palm-sweating ecstasy, we ought to be free to conclude, using precisely the same reasoning, that biological life had an intelligent cause.
You know that the critics of ID are really flustered, however, when they start making excellent arguments in favor of ID. In a Seattle Town Hall debate, University of Washington professor Peter Ward tried to discredit ID by pointing to a biochemist named Steve Benner, who has devised new ways of encoding genetic information in DNA. Ward was blissfully unaware that the fact that Benner has been able to this is a powerful argument FOR Intelligent Design, not AGAINST it. Why? Because Benner employed his INTELLIGENCE to DESIGN his system. Benner's accomplishment demonstrates precisely what proponents of ID have been saying for years: Intelligence is required to produce and encode information. For Benner's research to serve as a good argument AGAINST Intelligent Design, Benner would have to be as dumb as a box of rocks; but I seriously doubt that calling Steve Benner an idiot was really what Peter Ward had in mind.
Such egregious contradictions demonstrate that when a particular paradigm must be protected, logical consistency is no longer required. And yes, that's ironic as well because while logic and science are supposed to go hand-in-hand, the ID critics who claim to be defending science on the one hand, are the ones who have abandoned logic on the other.