482 U.S. 578 (1987)

EDWARDS, GOVERNOR OF LOUISIANA, ET AL.
v.
AGUILLARD ET AL.

No. 85-1513.

Supreme Court of United States.

Argued December 10, 1986 Decided June 19, 1987 APPEAL FROM THE UNITED STATES COURT OF APPEALS FOR THE FIFTH CIRCUIT

*579 Wendell R. Bird, Special Assistant Attorney General of Georgia, argued the cause for appellants. With him on the briefs were A. Morgan Brian, Jr., and Thomas T. Anderson, Special Assistant Attorneys General, Kendall L. Vick, and *580 Patricia Nalley Bowers, Assistant Attorney General of Louisiana.

Jay Topkis argued the cause for appellees. With him on the brief was John DiGiulio, Samuel I. Rosenberg, Allen Blumstein, Gerard E. Harper, Jack D. Novik, Burt Neuborne, Norman Dorsen, John Sexton, and Ron Wilson.^[*]

Briefs of amici curiae urging affirmance were filed for the State of New York et al. by Robert Abrams, Attorney General of New York, O. Peter Sherwood, Solicitor General, Paul M. Glickman, Jane Levine, Suzanne Lynn, and Marla Tepper, Assistant Attorneys General, and Neil F. Hartigan, Attorney General of Illinois; for the American Association of University Professors et al. by Ann H. Franke, Jacqueline W. Mintz, and Sheldon E. Steinbach; for the American Federation of Teachers, AFL-CIO, by Bruce A. Miller and Stuart M. Israel; for the American Jewish Congress et al. by Marvin E. Frankel, Marc D. Stern, and Ronald A. Krauss; for Americans United for Separation of Church and State et al. by Lee Boothby, Samuel Rabinove, Richard T. Foltin, and James M. Parker; for the Anti-Defamation League of B'nai B'rith et al. by Ruti G. Teitel, Justin J. Finger, Jeffrey P. Sinensky, and Steven M. Freeman; for the National Academy of Sciences by Barry H. Garfinkel and Mark Herlihy; for the New York Committee for Public Education and Religious Liberty by Leo Pfeffer; for People for the American Way et al. by Timothy B. Dyk, A. Douglas Melamed, and Kerry W. Kircher; for the Spartacist League et al. by Rachel H. Wolkenstein; and for 72 Nobel Laureates et al. by Walter B. Slocombe.

Briefs of amici curiae were filed for the Rabbinical Alliance of America et al. by John W. Whitehead and Larry L. Crain; and for Reverend Bill McLean et al. by Philip E. Kaplan.

JUSTICE BRENNAN delivered the opinion of the Court.^[†]

The question for decision is whether Louisiana's "Balanced Treatment for Creation-Science and Evolution-Science in Public School Instruction" Act (Creationism Act), La. Rev. Stat. Ann. §§ 17:286.1-17:286.7 (West 1982), is facially invalid *581 as violative of the Establishment Clause of the First Amendment.

I

The Creationism Act forbids the teaching of the theory of evolution in public schools unless accompanied by instruction in "creation science." § 17:286.4A. No school is required to teach evolution or creation science. If either is taught, however, the other must also be taught. Ibid. The theories of evolution and creation science are statutorily defined as "the scientific evidences for [creation or evolution] and inferences from those scientific evidences." §§ 17.286.3(2) and (3).

Appellees, who include parents of children attending Louisiana public schools, Louisiana teachers, and religious leaders, challenged the constitutionality of the Act in District Court, seeking an injunction and declaratory relief.^[1] Appellants, Louisiana officials charged with implementing the Act, defended on the ground that the purpose of the Act is to protect a legitimate secular interest, namely, academic freedom.^[2] Appellees attacked the Act as facially invalid because *582 it violated the Establishment Clause and made a motion for summary judgment. The District Court granted the motion. Aguillard v. Treen, 634 F. Supp. 426 (ED La. 1985). The court held that there can be no valid secular reason for prohibiting the teaching of evolution, a theory historically opposed by some religious denominations. The court further concluded that "the teaching of `creation-science' and `creationism,' as contemplated by the statute, involves teaching `tailored to the principles' of a particular religious sect or group of sects." Id., at 427 (citing Epperson v. Arkansas, 393 U. S. 97, 106 (1968)). The District Court therefore held that the Creationism Act violated the Establishment Clause either because it prohibited the teaching of evolution or because it required the teaching of creation science with the purpose of advancing a particular religious doctrine.

The Court of Appeals affirmed. 765 F. 2d 1251 (CA5 1985). The court observed that the statute's avowed purpose of protecting academic freedom was inconsistent with requiring, upon risk of sanction, the teaching of creation science whenever evolution is taught. Id., at 1257. The court found that the Louisiana Legislature's actual intent was "to discredit evolution by counterbalancing its teaching at every turn with the teaching of creationism, a religious belief." Ibid. Because the Creationism Act was thus a law furthering a particular religious belief, the Court of Appeals held that the Act violated the Establishment Clause. A suggestion for rehearing en banc was denied over a dissent. 778 F. 2d 225 (CA5 1985). We noted probable jurisdiction, 476 U. S. 1103 (1986), and now affirm.

II

The Establishment Clause forbids the enactment of any law "respecting an establishment of religion."^[3] The Court *583 has applied a three-pronged test to determine whether legislation comports with the Establishment Clause. First, the legislature must have adopted the law with a secular purpose. Second, the statute's principal or primary effect must be one that neither advances nor inhibits religion. Third, the statute must not result in an excessive entanglement of government with religion. Lemon v. Kurtzman, 403 U. S. 602, 612-613 (1971).^[4] State action violates the Establishment Clause if it fails to satisfy any of these prongs.

In this case, the Court must determine whether the Establishment Clause was violated in the special context of the public elementary and secondary school system. States and local school boards are generally afforded considerable discretion in operating public schools. See Bethel School Dist. No. 403 v. Fraser, 478 U. S. 675, 683 (1986); id., at 687 (BRENNAN, J., concurring in judgment); Tinker v. Des Moines Independent Community School Dist., 393 U. S. 503, 507 (1969). "At the same time . . . we have necessarily recognized that the discretion of the States and local school boards in matters of education must be exercised in a manner that comports with the transcendent imperatives of the First Amendment." Board of Education, Island Trees Union Free School Dist. No. 26 v. Pico, 457 U. S. 853, 864 (1982).

The Court has been particularly vigilant in monitoring compliance with the Establishment Clause in elementary and *584 secondary schools. Families entrust public schools with the education of their children, but condition their trust on the understanding that the classroom will not purposely be used to advance religious views that may conflict with the private beliefs of the student and his or her family. Students in such institutions are impressionable and their attendance is involuntary. See, e. g., Grand Rapids School Dist. v. Ball, 473 U. S. 373, 383 (1985); Wallace v. Jaffree, 472 U. S. 38, 60, n. 51 (1985); Meek v. Pittenger, 421 U. S. 349, 369 (1975); Abington School Dist. v. Schempp, 374 U. S. 203, 252-253 (1963) (BRENNAN, J., concurring). The State exerts great authority and coercive power through mandatory attendance requirements, and because of the students' emulation of teachers as role models and the children's susceptibility to peer pressure.^[5] See Bethel School Dist. No. 403 v. Fraser, supra, at 683; Wallace v. Jaffree, supra, at 81 (O'CONNOR, J., concurring in judgment). Furthermore, "[t]he public school is at once the symbol of our democracy and the most pervasive means for promoting our common destiny. In no activity of the State is it more vital to keep out divisive forces than in its schools . . . ." Illinois ex rel. McCollum v. Board of Education, 333 U. S. 203, 231 (1948) (opinion of Frankfurter, J.).

Consequently, the Court has been required often to invalidate statutes which advance religion in public elementary and secondary schools. See, e. g., Grand Rapids School Dist. v. Ball, supra (school district's use of religious school teachers in public schools); Wallace v. Jaffree, supra (Alabama statute authorizing moment of silence for school prayer); Stone v. *585 Graham, 449 U. S. 39 (1980) (posting copy of Ten Commandments on public classroom wall); Epperson v. Arkansas, 393 U. S. 97 (1968) (statute forbidding teaching of evolution); Abington School Dist. v. Schempp, supra (daily reading of Bible); Engel v. Vitale, 370 U. S. 421, 430 (1962) (recitation of "denominationally neutral" prayer).

Therefore, in employing the three-pronged Lemon test, we must do so mindful of the particular concerns that arise in the context of public elementary and secondary schools. We now turn to the evaluation of the Act under the Lemon test.

III

Lemon's first prong focuses on the purpose that animated adoption of the Act. "The purpose prong of the Lemon test asks whether government's actual purpose is to endorse or disapprove of religion." Lynch v. Donnelly, 465 U. S. 668, 690 (1984) (O'CONNOR, J., concurring). A governmental intention to promote religion is clear when the State enacts a law to serve a religious purpose. This intention may be evidenced by promotion of religion in general, see Wallace v. Jaffree, supra, at 52-53 (Establishment Clause protects individual freedom of conscience "to select any religious faith or none at all"), or by advancement of a particular religious belief, e. g., Stone v. Graham, supra, at 41 (invalidating requirement to post Ten Commandments, which are "undeniably a sacred text in the Jewish and Christian faiths") (footnote omitted); Epperson v. Arkansas, supra, at 106 (holding that banning the teaching of evolution in public schools violates the First Amendment since "teaching and learning" must not "be tailored to the principles or prohibitions of any religious sect or dogma"). If the law was enacted for the purpose of endorsing religion, "no consideration of the second or third criteria [of Lemon] is necessary." Wallace v. Jaffree, supra, at 56. In this case, appellants have identified no clear secular purpose for the Louisiana Act.

*586 True, the Act's stated purpose is to protect academic freedom. La. Rev. Stat. Ann. § 17:286.2 (West 1982). This phrase might, in common parlance, be understood as referring to enhancing the freedom of teachers to teach what they will. The Court of Appeals, however, correctly concluded that the Act was not designed to further that goal.^[6] We find no merit in the State's argument that the "legislature may not [have] use[d] the terms `academic freedom' in the correct legal sense. They might have [had] in mind, instead, a basic concept of fairness; teaching all of the evidence." Tr. of Oral Arg. 60. Even if "academic freedom" is read to mean "teaching all of the evidence" with respect to the origin of human beings, the Act does not further this purpose. The goal of providing a more comprehensive science curriculum is not furthered either by outlawing the teaching of evolution or by requiring the teaching of creation science.

A

While the Court is normally deferential to a State's articulation of a secular purpose, it is required that the statement *587 of such purpose be sincere and not a sham. See Wallace v. Jaffree, 472 U. S., at 64 (POWELL, J., concurring); id., at 75 (O'CONNOR, J., concurring in judgment); Stone v. Graham, supra, at 41; Abington School Dist. v. Schempp, 374 U. S., at 223-224. As JUSTICE O'CONNOR stated in Wallace: "It is not a trivial matter, however, to require that the legislature manifest a secular purpose and omit all sectarian endorsements from its laws. That requirement is precisely tailored to the Establishment Clause's purpose of assuring that Government not intentionally endorse religion or a religious practice." 472 U. S., at 75 (concurring in judgment).

It is clear from the legislative history that the purpose of the legislative sponsor, Senator Bill Keith, was to narrow the science curriculum. During the legislative hearings, Senator Keith stated: "My preference would be that neither [creationism nor evolution] be taught." 2 App. E-621. Such a ban on teaching does not promote — indeed, it undermines — the provision of a comprehensive scientific education.

It is equally clear that requiring schools to teach creation science with evolution does not advance academic freedom. The Act does not grant teachers a flexibility that they did not already possess to supplant the present science curriculum with the presentation of theories, besides evolution, about the origin of life. Indeed, the Court of Appeals found that no law prohibited Louisiana public school teachers from teaching any scientific theory. 765 F. 2d, at 1257. As the president of the Louisiana Science Teachers Association testified, "[a]ny scientific concept that's based on established fact can be included in our curriculum already, and no legislation allowing this is necessary." 2 App. E-616. The Act provides Louisiana schoolteachers with no new authority. Thus the stated purpose is not furthered by it.

The Alabama statute held unconstitutional in Wallace v. Jaffree, supra, is analogous. In Wallace, the State characterized its new law as one designed to provide a 1-minute period for meditation. We rejected that stated purpose as insufficient, *588 because a previously adopted Alabama law already provided for such a 1-minute period. Thus, in this case, as in Wallace, "[a]ppellants have not identified any secular purpose that was not fully served by [existing state law] before the enactment of [the statute in question]." 472 U. S., at 59.

Furthermore, the goal of basic "fairness" is hardly furthered by the Act's discriminatory preference for the teaching of creation science and against the teaching of evolution.^[7] While requiring that curriculum guides be developed for creation science, the Act says nothing of comparable guides for evolution. La. Rev. Stat. Ann. § 17:286.7A (West 1982). Similarly, resource services are supplied for creation science but not for evolution. § 17:286.7B. Only "creation scientists" can serve on the panel that supplies the resource services. Ibid. The Act forbids school boards to discriminate against anyone who "chooses to be a creation-scientist" or to teach "creationism," but fails to protect those who choose to teach evolution or any other noncreation science theory, or who refuse to teach creation science. § 17:286.4C.

If the Louisiana Legislature's purpose was solely to maximize the comprehensiveness and effectiveness of science instruction, it would have encouraged the teaching of all scientific theories about the origins of humankind.^[8] But under *589 the Act's requirements, teachers who were once free to teach any and all facets of this subject are now unable to do so. Moreover, the Act fails even to ensure that creation science will be taught, but instead requires the teaching of this theory only when the theory of evolution is taught. Thus we agree with the Court of Appeals' conclusion that the Act does not serve to protect academic freedom, but has the distinctly different purpose of discrediting "evolution by counterbalancing its teaching at every turn with the teaching of creationism . . . ." 765 F. 2d, at 1257.

B

Stone v. Graham invalidated the State's requirement that the Ten Commandments be posted in public classrooms. "The Ten Commandments are undeniably a sacred text in the Jewish and Christian faiths, and no legislative recitation of a supposed secular purpose can blind us to that fact." 449 U. S., at 41 (footnote omitted). As a result, the contention that the law was designed to provide instruction on a "fundamental legal code" was "not sufficient to avoid conflict with the First Amendment." Ibid. Similarly Abington School Dist. v. Schempp held unconstitutional a statute "requiring the selection and reading at the opening of the school day of verses from the Holy Bible and the recitation of the Lord's Prayer by the students in unison," despite the proffer of such secular purposes as the "promotion of moral values, the contradiction *590 to the materialistic trends of our times, the perpetuation of our institutions and the teaching of literature." 374 U. S., at 223.

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.<sup>[10]</sup> 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 *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 *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[s] 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]*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 *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]

IV

Appellants contend that genuine issues of material fact remain in dispute, and therefore the District Court erred in granting summary judgment. Federal Rule of Civil Procedure 56(c) provides that summary judgment "shall be rendered forthwith if the pleadings, depositions, answers to interrogatories, and admissions on file, together with the affidavits, if any, show that there is no genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law." A court's finding of improper purpose behind a statute is appropriately determined by the statute on its face, its legislative history, or its interpretation by a responsible administrative agency. See, e. g., Wallace v. Jaffree, 472 U. S., at 56-61; Stone v. Graham, 449 U. S., at 41-42; Epperson v. Arkansas, 393 U. S., at 103-109. The plain meaning of the statute's words, enlightened by their context and the contemporaneous legislative history, can control the determination of legislative purpose. See Wallace v. Jaffree, supra, at 74 (O'CONNOR, J., concurring in judgment); Richards v. United States, 369 U. S. 1, 9 (1962); Jay *595 v. Boyd, 351 U. S. 345, 357 (1956). Moreover, in determining the legislative purpose of a statute, the Court has also considered the historical context of the statute, e. g., Epperson v. Arkansas, supra, and the specific sequence of events leading to passage of the statute, e. g., Arlington Heights v. Metropolitan Housing Dev. Corp., 429 U. S. 252 (1977).

In this case, appellees' motion for summary judgment rested on the plain language of the Creationism Act, the legislative history and historical context of the Act, the specific sequence of events leading to the passage of the Act, the State Board's report on a survey of school superintendents, and the correspondence between the Act's legislative sponsor and its key witnesses. Appellants contend that affidavits made by two scientists, two theologians, and an education administrator raise a genuine issue of material fact and that summary judgment was therefore barred. The affidavits define creation science as "origin through abrupt appearance in complex form" and allege that such a viewpoint constitutes a true scientific theory. See App. to Brief for Appellants A-7 to A-40.

We agree with the lower courts that these affidavits do not raise a genuine issue of material fact. The existence of "uncontroverted affidavits" does not bar summary judgment.^[16] Moreover, the postenactment testimony of outside experts is of little use in determining the Louisiana Legislature's purpose in enacting this statute. The Louisiana Legislature did hear and rely on scientific experts in passing the bill,^[17] but none of the persons making the affidavits produced by the appellants *596 participated in or contributed to the enactment of the law or its implementation.^[18] The District Court, in its discretion, properly concluded that a Monday-morning "battle of the experts" over possible technical meanings of terms in the statute would not illuminate the contemporaneous purpose of the Louisiana Legislature when it made the law.^[19] We therefore conclude that the District Court did not err in finding that appellants failed to raise a genuine issue of material fact, and in granting summary judgment.^[20]

V

The Louisiana Creationism Act advances a religious doctrine by requiring either the banishment of the theory of evolution from public school classrooms or the presentation of a religious viewpoint that rejects evolution in its entirety. *597A The Act violates the Establishment Clause of the First Amendment because it seeks to employ the symbolic and financial support of government to achieve a religious purpose. The judgment of the Court of Appeals therefore is

Affirmed.

*597B JUSTICE POWELL, with whom JUSTICE O'CONNOR joins, concurring.

I write separately to note certain aspects of the legislative history, and to emphasize that nothing in the Court's opinion diminishes the traditionally broad discretion accorded state and local school officials in the selection of the public school curriculum.

I

This Court consistently has applied the three-pronged test of Lemon v. Kurtzman, 403 U. S. 602 (1971), to determine whether a particular state action violates the Establishment Clause of the Constitution.^[1] See, e. g., Grand Rapids School Dist. v. Ball, 473 U. S. 373, 383 (1985) ("We have particularly relied on Lemon in every case involving the sensitive relationship between government and religion in the education of our children"). The first requirement of the Lemon test is that the challenged statute have a "secular legislative purpose." Lemon v. Kurtzman, supra, at 612. See Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S. 756, 773 (1973). If no valid secular purpose can be identified, then the statute violates the Establishment Clause.

A

"The starting point in every case involving construction of a statute is the language itself." Blue Chip Stamps v. Manor Drug Stores, 421 U. S. 723, 756 (1975) (POWELL, J., *598 concurring). The Balanced Treatment for Creation-Science and Evolution-Science Act (Act or Balanced Treatment Act), La. Rev. Stat. Ann. § 17:286.1 et seq. (West 1982), provides in part:

"[P]ublic schools within [the] state shall give balanced treatment to creation-science and to evolution-science. Balanced treatment of these two models shall be given in classroom lectures taken as a whole for each course, in textbook materials taken as a whole for each course, in library materials taken as a whole for the sciences and taken as a whole for the humanities, and in other educational programs in public schools, to the extent that such lectures, textbooks, library materials, or educational programs deal in any way with the subject of the origin of man, life, the earth, or the universe. When creation or evolution is taught, each shall be taught as a theory, rather than as proven scientific fact." § 17:286.4(A).

"Balanced treatment" means "providing whatever information and instruction in both creation and evolution models the classroom teacher determines is necessary and appropriate to provide insight into both theories in view of the textbooks and other instructional materials available for use in his classroom." § 17:286.3(1). "Creation-science" is defined as "the scientific evidences for creation and inferences from those scientific evidences." § 17:286.3(2). "Evolution-science" means "the scientific evidences for evolution and inferences from those scientific evidences." § 17:286.3(3).

Although the Act requires the teaching of the scientific evidences of both creation and evolution whenever either is taught, it does not define either term. "A fundamental canon of statutory construction is that, unless otherwise defined, words will be interpreted as taking their ordinary, contemporary, common meaning." Perrin v. United States, 444 U. S. 37, 42 (1979). The "doctrine or theory of creation" is commonly defined as "holding that matter, the various forms of life, and the world were created by a transcendent God out *599 of nothing." Webster's Third New International Dictionary 532 (unabridged 1981). "Evolution" is defined as "the theory that the various types of animals and plants have their origin in other preexisting types, the distinguishable differences being due to modifications in successive generations." Id., at 789. Thus, the Balanced Treatment Act mandates that public schools present the scientific evidence to support a theory of divine creation whenever they present the scientific evidence to support the theory of evolution. "[C]oncepts concerning God or a supreme being of some sort are manifestly religious . . . . These concepts do not shed that religiosity merely because they are presented as a philosophy or as a science." Malnak v. Yogi, 440 F. Supp. 1284, 1322 (NJ 1977), aff'd per curiam, 592 F. 2d 197 (CA3 1979). From the face of the statute, a purpose to advance a religious belief is apparent.

A religious purpose alone is not enough to invalidate an act of a state legislature. The religious purpose must predominate. See Wallace v. Jaffree, 472 U. S. 38, 56 (1985); id., at 64 (POWELL, J., concurring); Lynch v. Donnelly, 465 U. S. 668, 681, n. 6 (1984). The Act contains a statement of purpose: to "protec[t] academic freedom." § 17:286.2. This statement is puzzling. Of course, the "academic freedom" of teachers to present information in public schools, and students to receive it, is broad. But it necessarily is circumscribed by the Establishment Clause. "Academic freedom" does not encompass the right of a legislature to structure the public school curriculum in order to advance a particular religious belief. Epperson v. Arkansas, 393 U. S. 97, 106 (1968). Nevertheless, I read this statement in the Act as rendering the purpose of the statute at least ambiguous. Accordingly, I proceed to review the legislative history of the Act.

B

In June 1980, Senator Bill Keith introduced Senate Bill 956 in the Louisiana Legislature. The stated purpose of the bill *600 was to "assure academic freedom by requiring the teaching of the theory of creation ex nihilo in all public schools where the theory of evolution is taught." 1 App. E-1.^[2] The bill defined the "theory of creation ex nihilo" as "the belief that the origin of the elements, the galaxy, the solar system, of life, of all the species of plants and animals, the origin of man, and the origin of all things and their processes and relationships were created ex nihilo and fixed by God." Id., at E-1a — E-1b. This theory was referred to by Senator Keith as "scientific creationism." Id.,