Intelligent Design is dismissed as a "pseudo-science" - a form of creationism that lacks empirical support and offers no testable or tenable hypotheses, so is not science.
Detailed scientific examination has rebutted the claims that evolutionary explanations are inadequate, and this premise of intelligent design—that evidence against evolution constitutes evidence for design—is a false dichotomy. It is asserted that ID challenges the methodological naturalism inherent in modern science though proponents concede that they have yet to produce a scientific theory.
Critique of Fine-tuning of Cosmological Constants:
The argument presupposes intelligent beings could not come about from material arrangements other than carbon-based biology. Since cosmological constants are within a highly-improbable range only for life as we know it, it is not valid to extrapolate to the probability that intelligent minds of any sort would occur naturally.
If the Multiverse hypothesis of quantum mechanics is true, then there is no need to explain the uncanny anthropic tuning of our Universe. All possible Universes exist with equal probability and we just happen to be one of the few where intelligent life forms.
Finally, the Universe remains largely inhospitable. Some constants such as the amount of entropy in the early Universe are very far from being advantageous for life formation. An intelligent God could have made an even better job at designing a Universe for humans to proliferate.
Critique of Irreducible Complexity:
Critics point out that the irreducible complexity argument assumes that the necessary parts of a system have always been necessary and therefore could not have been added sequentially. They argue that something that is at first merely advantageous can later become necessary as other components change. Furthermore, they argue, evolution often proceeds by altering preexisting parts or by removing them from a system, rather than by adding them. This is sometimes called the "scaffolding objection" by an analogy with scaffolding, which can support an "irreducibly complex" building until it is complete and able to stand on its own. Behe has acknowledged using "sloppy prose", and that his "argument against Darwinism does not add up to a logical proof." Irreducible complexity has remained a popular argument among advocates of intelligent design; in the Dover trial, the court held that "Professor Behe's claim for irreducible complexity has been refuted in peer-reviewed research papers and has been rejected by the scientific community at large."
Critique of Specified Complexity:
The conceptual soundness of Dembski's specified complexity/CSI argument has been discredited in the scientific and mathematical communities. Specified complexity has yet to be shown to have wide applications in other fields, as Dembski asserts. John Wilkins and Wesley R. Elsberry characterize Dembski's "explanatory filter" as eliminative because it eliminates explanations sequentially: first regularity, then chance, finally defaulting to design. They argue that this procedure is flawed as a model for scientific inference because the asymmetric way it treats the different possible explanations renders it prone to making false conclusions.
Richard Dawkins, another critic of intelligent design, argues in The God Delusion (2006) that allowing for an intelligent designer to account for unlikely complexity only postpones the problem, as such a designer would need to be at least as complex. Other scientists have argued that evolution through selection is better able to explain the observed complexity, as is evident from the use of selective evolution to design certain electronic, aeronautic and automotive systems that are considered problems too complex for human "intelligent designers".