As in Stone and Abington, we need not be blind in this case to the legislature's preeminent religious purpose in enacting this statute. There is a historic and contemporaneous link between the teachings of certain religious denominations and the teaching of evolution. 9 It was this link that concerned the Court in Epperson v. Arkansas, 393 U.S. 97 (1968), which also involved a facial challenge to a statute regulating the teaching of evolution. In that case, the Court reviewed an Arkansas statute that made it unlawful for an instructor to teach evolution or to use a textbook that referred to this scientific theory. Although the Arkansas antievolution law did not explicitly state its predominate religious purpose, the Court could not ignore that "[t]he statute was a product of the upsurge of `fundamentalist' religious fervor" that has long viewed this particular scientific theory as contradicting the literal interpretation of the Bible. Id., at 98, 106-107. 10 After reviewing the history of antievolution statutes, the Court determined that "there can be no doubt that the motivation for the [Arkansas] law was the same [as other antievolution statutes]: to suppress the teaching of a theory which, it was thought, `denied' the divine creation of man." Id., at 109. The Court found that there can be no legitimate [482 U.S. 578, 591] state interest in protecting particular religions from scientific views "distasteful to them," id., at 107 (citation omitted), and concluded "that the First Amendment does not permit the State to require that teaching and learning must be tailored to the principles or prohibitions of any religious sect or dogma," id., at 106.
These same historic and contemporaneous antagonisms between the teachings of certain religious denominations and the teaching of evolution are present in this case. The preeminent purpose of the Louisiana Legislature was clearly to advance the religious viewpoint that a supernatural being created humankind. 11 The term "creation science" was defined as embracing this particular religious doctrine by those responsible for the passage of the Creationism Act. Senator Keith's leading expert on creation science, Edward Boudreaux, testified at the legislative hearings that the theory of creation science included belief in the existence of a supernatural creator. See 1 App. E-421 - E-422 (noting that "creation scientists" point to high probability that life was "created by an intelligent mind"). 12 Senator Keith also cited testimony from other experts to support the creation-science view that "a creator [was] responsible for the universe and everything in it." 13 2 App. E-497. The legislative history [482 U.S. 578, 592] therefore reveals that the term "creation science," as contemplated by the legislature that adopted this Act, embodies the religious belief that a supernatural creator was responsible for the creation of humankind.
Furthermore, it is not happenstance that the legislature required the teaching of a theory that coincided with this religious view. The legislative history documents that the Act's primary purpose was to change the science curriculum of public schools in order to provide persuasive advantage to a particular religious doctrine that rejects the factual basis of evolution in its entirety. The sponsor of the Creationism Act, Senator Keith, explained during the legislative hearings that his disdain for the theory of evolution resulted from the support that evolution supplied to views contrary to his own religious beliefs. According to Senator Keith, the theory of evolution was consonant with the "cardinal principle of religious humanism, secular humanism, theological liberalism, aetheistism [sic]." 1 App. E-312-E-313; see also 2 App. E-499-E-500. The state senator repeatedly stated that scientific evidence supporting his religious views should be included in the public school curriculum to redress the fact that the theory of evolution incidentally coincided with what he characterized as religious beliefs antithetical to his own. 14 [482 U.S. 578, 593] The legislation therefore sought to alter the science curriculum to reflect endorsement of a religious view that is antagonistic to the theory of evolution.
In this case, the purpose of the Creationism Act was to restructure the science curriculum to conform with a particular religious viewpoint. Out of many possible science subjects taught in the public schools, the legislature chose to affect the teaching of the one scientific theory that historically has been opposed by certain religious sects. As in Epperson, the legislature passed the Act to give preference to those religious groups which have as one of their tenets the creation of humankind by a divine creator. The "overriding fact" that confronted the Court in Epperson was "that Arkansas' law selects from the body of knowledge a particular segment which it proscribes for the sole reason that it is deemed to conflict with . . . a particular interpretation of the Book of Genesis by a particular religious group." 393 U.S., at 103 . Similarly, the Creationism Act is designed either to promote the theory of creation science which embodies a particular religious tenet by requiring that creation science be taught whenever evolution is taught or to prohibit the teaching of a scientific theory disfavored by certain religious sects by forbidding the teaching of evolution when creation science is not also taught. The Establishment Clause, however, "forbids alike the preference of a religious doctrine or the prohibition of theory which is deemed antagonistic to a particular dogma." Id., at 106-107 (emphasis added). Because the primary purpose of the Creationism Act is to advance a particular religious belief, the Act endorses religion in violation of the First Amendment.
We do not imply that a legislature could never require that scientific critiques of prevailing scientific theories be taught. Indeed, the Court acknowledged in Stone that its decision [482 U.S. 578, 594] forbidding the posting of the Ten Commandments did not mean that no use could ever be made of the Ten Commandments, or that the Ten Commandments played an exclusively religious role in the history of Western Civilization. 449 U.S., at 42 . In a similar way, teaching a variety of scientific theories about the origins of humankind to schoolchildren might be validly done with the clear secular intent of enhancing the effectiveness of science instruction. But because the primary purpose of the Creationism Act is to endorse a particular religious doctrine, the Act furthers religion in violation of the Establishment Clause. 15