The Intelligent Design debate centers on three issues:
1. whether the definition of science is broad enough to allow for theories of origins which incorporate the acts of an intelligent designer
2. whether the evidence supports such theories
3. whether the teaching of such theories is appropriate in public education.
Intelligent Design supporters generally hold that science must allow for both natural and supernatural explanations of phenomena. They assert that excluding supernatural explanations artificially limits the realm of possibilities, particularly where naturalistic explanations fail to explain certain phenomena. Supernatural explanations provide a very simple and parsimonious explanation for the origins of life and the universe. Proponents claim that the evidence strongly supports such explanations, as instances of so-called irreducible complexity and specified complexity appear to make it highly unreasonable that the full complexity and diversity of life came about solely through natural means.
Finally, supporters hold that religious neutrality requires the teaching of both evolution and Intelligent Design in schools, because teaching only evolution unfairly discriminates against those holding the Creationist beliefs. Teaching both, Intelligent Design supporters argue, allows for a scientific basis for religious belief, without causing the state to actually promote a religious belief.
According to critics of Intelligent Design, not only has Intelligent Design failed to establish reasonable doubt in its proposed shortcomings of accepted scientific theories, but it has not even presented a case worth taking seriously. Critics of Intelligent Design argue that Intelligent Design has not presented a credible case for the public policy utility of presenting Intelligent Design in education. More broadly, critics maintain that it has not met the minimum legal standard of not being a "clear" attempt to establish religion, which in the United States is constitutionally forbidden. Scientists argue that those advocating "scientific" treatment of "supernatural" phenomena are grossly misunderstanding the issue, and indeed misunderstand the nature and purpose of science itself. Furthermore, if one were to take the proponents of "equal time for all theories" at their word, there would be no logical limit to the number of potential "theories" to be taught in the public school system. While Christian fundamentalists imagine their God to be the only deity to be referenced, a cursory examination of mankind's belief systems reveals that there is a very large number of potential supernatural "explanations" for the emergence and organization of life on earth, none of which have any empirical support and all of which therefore are equally deserving of promotion as Intelligent Design. Proponents of Intelligent Design, however, rarely if ever appear to note such alternative theological/supernatural possibilities, defaulting invariably to their particular interpretation of the Christian God.
Between these two positions there is a large body of opinion that does not condone the teaching of what is considered unscientific or questionable material, but is generally sympathetic to the position of Deism/Theism and therefore desires some compromise between the two. The nominal points of contention are seen as being proxies for other issues. Many Intelligent Design followers are quite open about their view that "Scientism" is itself a religion that promotes secularism and materialism in an attempt to erase religion from public life and view their work in the promotion of Intelligent Design as a way to return religion to a central role in education and other public spheres. Some allege that this larger debate is often the subtext for arguments made over Intelligent Design, though others note that Intelligent Design serves as an effective proxy for the religious beliefs of prominent Intelligent Design proponents in their efforts to advance their religious point of view within society.
