Mr. Justice Stewart
announced the judgment of the Court and delivered the opinion of the Court (Parts I, II, IV, and V), together with an opinion (Part III), in which Mb. Justice Blackmun and Mb. Justice Powell, joined.
This case requires us to determine once again whether a state law providing assistance to nonpublic, church-related, elementary and secondary schools is constitutional under the Establishment Clause of the First Amendment, made applicable to the States by the Fourteenth Amendment. Murdock v. Pennsylvania, 319 U. S. 105, 108; Cantwell v. Connecticut, 310 U. S. 296, 303.
I
With the stated purpose of assuring that every schoolchild in the Commonwealth will equitably share in the benefits of auxiliary services, textbooks, and instructional material provided free of charge to children attending public schools, the Pennsylvania General Assembly in 1972 added Acts 194 and 195, July 12, 1972, Pa. Stat. Ann., Tit. 24, § 9-972, to the Pennsylvania Public School Code of 1949, Pa. Stat. Ann., Tit. 24, §§ 1-101 to 27-2702.
Act 194 authorizes the Commonwealth to provide “auxiliary services” to all children enrolled in nonpublic elementary and secondary schools meeting Pennsylvania’s compulsory-attendance requirements. “Auxiliary services” include counseling, testing, and psychological services, speech and hearing therapy, teaching and related services for exceptional children, for remedial students, and for the educationally disadvantaged, “and such other secular, neutral, non-ideologieal services as are of benefit to nonpublic school children and are presently or hereafter provided for public school children of the Commonwealth.” Act 194 specifies that the teaching and services are to be provided in the nonpublic schools themselves by personnel drawn from the appropriate “intermediate unit,” part of the public school system of the Commonwealth established to provide special services to local school districts. See Pa. Stat. Ann., Tit. 24, §§ 9-951 to 9-971.
Act 195 authorizes the State Secretary of Education, either directly or through the intermediate units, to lend textbooks without charge to children attending nonpublic elementary and secondary schools that meet the Commonwealth’s compulsory-attendance requirements. The books that may be lent are limited to those “which are acceptable for use in any public, elementary, or secondary school of the Commonwealth.”
Act 195 also authorizes the Secretary of Education, pursuant to requests from the appropriate nonpublic school officials, to lend directly to the nonpublic schools “instructional materials and equipment, useful to the education” of nonpublic school children. “Instructional materials” are defined to include periodicals, photographs, maps, charts, sound recordings, films, “or any other printed and published materials of a similar nature.” “Instructional equipment,” as defined by the Act, includes projection equipment, recording equipment, and laboratory equipment.
On February 7, 1973, three individuals and four organizations filed a complaint in the District Court for the Eastern District of Pennsylvania challenging the constitutionality of Acts 194 and 195, and requesting an injunction prohibiting the expenditure of any funds under either statute. The complaint alleged that each Act “is a law respecting an establishment of religion in violation of the First Amendment” because each Act “authorizes and directs payments to or use of books, materials and equipment in schools which (1) are controlled by churches or religious organizations, (2) have as their purpose the teaching, propagation and promotion of a particular religious faith, (3) conduct their operations, curriculums and programs to fulfill that purpose, (4) impose religious restrictions on admissions, (5) require attendance at instruction in theology and religious doctrine, (6) require attendance at or participation in religious worship, (7) are an integral part of the religious mission of the sponsoring church, (8) have as a substantial or dominant purpose the inculcation of religious values, (9) impose religious restrictions on faculty appointments, and (10) impose religious restrictions on what the faculty may teach.” The Secretary of Education and the Treasurer of the Commonwealth were named as the defendants.
A three-judge court was convened pursuant to 28 U. S. C. §§ 2281, 2284. . After an evidentiary hearing, the court entered its final judgment. 374 F. Supp. 639. In that judgment the court unanimously upheld the constitutionality of the textbook loan program authorized by Act 195. 374 F. Supp., at 657-658. By a divided vote "the court also upheld the constitutionality of Act 194’s provision of auxiliary services to children in nonpublic elementary and secondary schools and Act 195’s authorization of loans of instructional materials directly to nonpublic elementary and secondary schools. 374 F. Supp., at 653-659. The court unanimously invalidated that portion of Act 195 authorizing the expenditure of commonwealth funds for the purchase of instructional equipment for loan to nonpublic schools, but only to the extent that the provision allowed the loan of equipment “which from its nature can be diverted to religious purposes.” 374 F. Supp., at 662. The court gave as examples projection and recording equipment. Id., at 660-661. By a vote of 2-1, the court upheld this provision of Act 195 insofar as it authorizes the loan of instructional equipment that cannot be readily diverted to religious uses. 374 F. Supp., at 660-661.
Except with respect to that provision of Act 195 which permits loan of instructional equipment capable of diversion, therefore, the plaintiffs’ request for preliminary and final injunctive relief was denied. The plaintiffs (hereinafter the appellants) appealed directly to this Court, pursuant to 28 U. S. C. § 1253. We noted probable jurisdiction. 419 U. S. 822.
II
In judging the constitutionality of the various forms of assistance authorized by Acts 194 and 195, the District Court applied the three-part test that has been clearly stated, if not easily applied, by this Court in recent Establishment Clause cases. See, e. g., Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S. 756, 772-773; Lemon v. Kurtzman, 403 U. S. 602, 612-613. First, the statute must have a secular legislative purpose. E. g., Epperson v. Arkansas, 393 U. S. 97. Second, it must have a “primary effect” that neither advances nor inhibits religion. E. g., School District of Abington Township v. Schempp, 374 U. S. 203. Third, the statute and its administration must avoid excessive government entanglement with religion. E. g., Walz v. Tax Comm’n, 397 U. S. 664.
These tests constitute a convenient, accurate distillation of this Court’s efforts over the past decades to evaluate a wide range of governmental action challenged as violative of the constitutional prohibition against laws “respecting an establishment of religion,” and thus provide the proper framework of analysis for the issues presented in the case before us. It is well to emphasize, however, that the tests must not be viewed as setting the precise limits to the necessary constitutional inquiry, but serve only as guidelines with which to identify instances in which the objectives of the Establishment Clause have been impaired. See Tilton v. Richardson, 403 U. S. 672, 677-678 (plurality opinion of Burger, C. J.).
Primary among the evils against which the Establishment Clause protects “have been ‘sponsorship, financial support, and active involvement of the sovereign in religious activity.’ Walz v. Tax Comm’n, supra, at 668; Lemon v. Kurtzman, supra, at 612.” Committee for Public Education & Religious Liberty v. Nyquist, supra, at 772. The Court has broadly stated that “[n]o tax in any amount, large or small, can be levied to support any religious activities or institutions, whatever they may be called, or whatever form they may adopt to teach or practice religion.” Everson v. Board of Education, 330 U. S. 1, 16. But it is clear that not all legislative programs that provide indirect or incidental benefit to a religious institution are prohibited by the Constitution. See Zorach v. Clauson, 343 U. S. 306, 312; Lemon v. Kurtzman, supra, at 614. “The problem, like many problems in constitutional law, is one of degree.” Zorach v. Clauson, supra, at 314.
Ill
The District Court held that the textbook loan provisions of Act 195 are constitutionally indistinguishable from the New York textbook loan program upheld in Board of Education v. Allen, 392 U. S. 236. We agree.
Approval of New York’s textbook loan program in the Allen case was based primarily on this Court’s earlier decision in Everson v. Board of Education, supra, holding that the constitutional prohibition against laws “respecting an establishment of religion” did not prevent “New Jersey from spending tax-raised funds to pay the bus fares of parochial school pupils as a part of a general program under which it pays the fares of pupils attending public and other schools.” 330 U. S., at 17. Similarly, the Court in Allen found that the New York textbook law “merely makes available to all children the benefits of a general program to lend school books free of charge. Books are furnished at the request of the pupil and ownership remains, at least technically, in the State. Thus no funds or books are furnished to parochial schools, and the financial benefit is to parents and children, not to schools.” 392 U. S., at 243-244. The Court conceded that provision of free textbooks might make it “more likely that some children choose to attend a sectarian school, but that was true of the state-paid bus fares in Everson and does not alone demonstrate an unconstitutional degree of support for a religious institution.” Id., at 244.
Like the New York program, the textbook provisions of Act 195 extend to all schoolchildren the benefits of Pennsylvania’s well-established policy of lending textbooks free of charge to elementary and secondary school students. As in Allen, Act 195 provides that the textbooks are to be lent directly to the student, not to the nonpublic school itself, although, again as in Allen, the administrative practice is to have student requests for the books filed initially with the nonpublic school and to have the school authorities prepare collective summaries of these requests which they forward to the appropriate public officials. See Board of Education v. Allen, supra, at 244 n. 6. Thus, the financial benefit of Pennsylvania’s textbook program, like New York’s, is to parents and children, not to the nonpublic schools.
Under New York law the books that could be lent were limited to textbooks “which are designated for use in any public, elementary or secondary schools of the state or are approved by any boards of education, trustees or other school authorities.” N. Y. Educ. Law § 701 (3). The law was construed by the New York Court of Appeals to apply solely to secular textbooks. Board of Education v. Allen, 20 N. Y. 2d 109, 117, 228 N. E. 2d 791, 794. Act 195 similarly limits the books that may be lent to “textbooks which are acceptable for use in any public, elementary, or secondary school of the Commonwealth.” Moreover, the record in the case before us, like the record in Allen, see, e. g., 392 U. S., at 244-245, 248, contains no suggestion that religious textbooks will be lent or that the books provided will be used for anything other than purely secular purposes.
In sum, the textbook loan provisions of Act 195 are in every material respect identical to the loan program approved in Allen. Pennsylvania, like New York, “merely makes available to all children the benefits of a general program to lend school books free of charge.” As such, those provisions of Act 195 do not offend the constitutional prohibition against laws “respecting an establishment of religion.”
IV
Although textbooks are lent only to students, Act 195 authorizes the loan of instructional material and equipment directly to qualifying nonpublic elementary and secondary schools in the Commonwealth. The appellants assert that such direct aid to Pennsylvania’s nonpublic schools, including church-related institutions, constitutes an impermissible establishment of religion.
Act 195 is accompanied by legislative findings that the welfare of the Commonwealth requires that present and future generations of schoolchildren be assured ample opportunity to develop their intellectual capacities. Act 195 is intended to further that objective by extending the benefits of free educational aids to every schoolchild in the Commonwealth, including nonpublic school students who constitute approximately one quarter of the schoolchildren in Pennsylvania. Act 195, § 1 (a), Pa. Stat. Ann., Tit. 24, § 9-972 (a). We accept the legitimacy of this secular legislative purpose. Cf. Lemon v. Kurtzman, 403 U. S., at 609, 613; Sloan v. Lemon, 413 U. S. 825, 829-830. But we agree with the appellants that the direct loan of instructional material and equipment has the unconstitutional primary effect of advancing religion because of the predominantly religious character of the schools benefiting from the Act.
The only requirement imposed on nonpublic schools to qualify for loans of instructional material and equipment is that they satisfy the Commonwealth’s compulsory-attendance law by providing, in the English language, the subjects and activities prescribed by the standards of the State Board of Education. Pa. Stat. Ann., Tit. 24, § 13-1327. Commonwealth officials, as a matter of state policy, do not inquire into the religious characteristics, if any, of the nonpublic schools requesting aid pursuant to Act 195. The Coordinator of Nonpublic School Services, the chief administrator of Acts 194 and 195, testified that a school would not be barred from receiving loans of instructional material and equipment even though its dominant purpose was the inculcation of religious values, even if it imposed religious restrictions on admissions or on faculty appointments, and even if it required attendance at classes in theology or at religious services. In fact, of the 1,320 nonpublic schools in Pennsylvania that comply with the requirements of the compulsory-attendance law and thus qualify for aid under Act 195, more than 75% are church-related or religiously affiliated educational institutions. Thus, the primary beneficiaries of Act 195’s instructional material and equipment loan provisions, like the beneficiaries of the “secular educational services” reimbursement program considered in Lemon v. Kurtzman, and the parent tuition-reimbursement plan considered in Sloan v. Lemon, are nonpublic schools with a predominant sectarian character.
It is, of course, true that as part of general legislation made available to all students, a State may include church-related schools in programs providing bus transportation, school lunches, and public health facilities— secular and nonideological services unrelated to the primary, religion-oriented educational function of the sectarian school. The indirect and incidental benefits to church-related schools from those programs do not offend the constitutional prohibition against establishment of religion. See, e. g., Everson v. Board of Education, 330 U. S. 1; Lemon v. Kurtzman, supra, at 616-617; Committee for Public Education <fe Religious Liberty v. Nyquist, 413 U. S., at 776. But the massive aid provided the church-related nonpublic schools of Pennsylvania by Act 195 is neither indirect nor incidental.
For the 1972-1973 school year the Commonwealth authorized just under $12 million of direct aid to the predominantly church-related nonpublic schools of Pennsylvania through the loan of instructional material and equipment pursuant to Act 195. To be sure, the material and equipment that are the subjects of the loan— maps, charts, and laboratory equipment, for example— are “self-polic[ing], in that starting as secular, nonideological and neutral, they will not change in use.” 374 F. Supp., at 660. But faced with the substantial amounts of direct support authorized by Act 195, it would simply ignore reality to attempt to separate secular educational functions from the predominantly religious role performed by many of Pennsylvania’s church-related elementary and secondary schools and to then characterize Act 195 as channeling aid to the secular without providing direct aid to the sectarian. Even though earmarked for secular purposes, “when it flows to an institution in which religion is so pervasive that a substantial portion of its functions are subsumed in the religious mission,” state aid has the impermissible primary effect of advancing religion. Hunt v. McNair, 413 U. S. 734, 743.
The church-related elementary and secondary schools that are the primary beneficiaries of Act 195’s instructional material and equipment loans typify such religion-pervasive institutions. The very purpose of many of those schools is to provide an integrated secular and religious education; the teaching process is, to a large extent, devoted to the inculcation of religious values and belief. See Lemon v. Kurtzman, 403 U. S., at 616-617. Substantial aid to the educational function of such schools, accordingly, necessarily results in aid to the sectarian school enterprise as a whole. “[T]he secular education those schools provide goes hand in hand with the religious mission that is the only reason for the schools’ existence. Within the institution, the two are inextricably intertwined.” Id., at 657 (opinion of Brennan, J.). See generally Freund, Public Aid to Parochial Schools, 82 Harv. L. Rev. 1680, 1688-1689. For this reason, Act 195’s direct aid to Pennsylvania’s predominantly church-related, nonpublic elementary and secondary schools, even though ostensibly limited to wholly neutral, secular instructional material and equipment, inescapably results in the direct and substantial advancement of religious activity, cf. Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S., at 781-783, and n. 39, and thus constitutes an impermissible establishment of religion.
y
Unlike Act 195, which provides only for the loan of teaching material and equipment, Act 194 authorizes the Secretáry of Education, through the intermediate units, to supply professional staff, as well as supportive materials, equipment, and personnel, to the nonpublic schools of the Commonwealth. The “auxiliary services” authorized by Act 194 — remedial and accelerated instruction, guidance counseling and testing, speech and hearing services — are provided directly to nonpublic school children with the appropriate special need. But the services are provided only on the nonpublic school premises, and only when “requested by nonpublic school representatives.” Department of Education, Commonwealth of Pennsylvania, Guidelines for the Administration of Acts 194 and 195, § 1.3..
The legislative findings accompanying Act 194 are virtually identical to those in Act 195: Act 194 is intended to assure full development of the intellectual capacities of the children of Pennsylvania by extending the benefits of free auxiliary services to all students in the Commonwealth. Act 194, § 1 (a), Pa. Stat. Ann., Tit. 24, § 9-972 (a). The appellants concede the validity of this secular legislative purpose. Nonetheless, they argue that Act 194 constitutes an impermissible establishment of religion because the auxiliary services are provided on the premises of predominantly church-related schools.
In rejecting the appellants’ argument, the District Court emphasized that “auxiliary services” are provided directly to the children involved and are expressly limited to those services which are secular, neutral, and nonideological. The court also noted that the instruction and counseling in question served only to supplement the basic, normal educational offerings of the qualifying nonpublic schools. Any benefits to church-related schools that may result from the provision of such services, the District Court concluded, are merely incidental and indirect, and thus not impermissible. See 374 F. Supp., at 656-657. The court also held that no continuing supervision of the personnel providing auxiliary services would be necessary to establish that Act 194’s secular limitations were observed or to guaranteé that a member of the auxiliary services staff had not “succumb [ed] to sectarianization of his or her professional work.” 374 F. Supp., at 657.
We need not decide whether substantial state expenditures to enrich the curricula of church-related elementary and secondary schools, like the expenditure of state funds to support the basic educational program of those schools, necessarily result in the direct and substantial advancement of religious activity. For decisions of this Court make clear that the District Court erred in relying entirely on the good faith and professionalism of the secular teachers and counselors functioning in church-related schools to ensure that a strictly nonideological posture is maintained.
In Earley v. DiCenso, a companion case to Lemon v. Kurtzman, supra, the Court invalidated a Rhode Island statute authorizing salary supplements for teachers of secular subjects in nonpublic schools. The Court expressly rejected the proposition, relied upon by the District Court in the case before us, that it was sufficient for the State to assume that teachers in church-related schools would succeed in segregating their religious beliefs from their secular educational duties.
“We need not and do not assume that teachers in parochial schools will be guilty of bad faith or any conscious design to evade the limitations imposed by the statute and the First Amendment....
“. . . But the potential for impermissible fostering of religion is present.... The State must be certain, given the Religion Clauses, that subsidized teachers do not inculcate religion....
“A comprehensive, discriminating, and continuing state surveillance will inevitably be required to ensure that these restrictions are obeyed and the First Amendment otherwise respected. . . 403 U. S., at 618-619.
The prophylactic contacts required to ensure that teachers play a strictly nonideological role, the Court held, necessarily give rise to a constitutionally intolerable degree of entanglement between church and state. Id., at 619. The same excessive entanglement would be required for Pennsylvania to be “certain,” as it must be, that Act 194 personnel do not advance the religious mission of the church-related schools in which they serve. Public Funds for Public Schools v. Marburger, 358 F. Supp. 29, 40-41, aff’d, 417 U. S. 961.
That Act 194 authorizes state funding of teachers only for remedial and exceptional students, and not for normal students participating in the core curriculum, does not distinguish this case from Earley v.DiCenso and Lemons. Kurtzman, supra. Whether the subject is “remedial reading,” “advanced reading,” or simply “reading,” a teacher remains a teacher, and the danger that religious doctrine will become intertwined with secular instruction persists. The likelihood of inadvertent fostering of religion may be less in a remedial arithmetic class than in a medieval history seminar, but a diminished probability of impermissible conduct is not sufficient: “The State must be certain, given the Religion Clauses, that subsidized teachers do not inculcate religion.” 403 U. S., at 619. And a state-subsidized guidance counselor is surely as likely as a state-subsidized chemistry teacher to fail on occasion to separate religious instruction and the advancement of religious beliefs from his secular educational responsibilities.
The fact that the teachers and counselors providing auxiliary services are employees of the public intermediate unit, rather than of the church-related schools in which they work, does not substantially eliminate the need for continuing surveillance. To be sure, auxiliary-services personnel, because not employed by the nonpublic schools, are not directly subject to the discipline of a religious authority. Cf. Lemon v. Kurtzman, 403 U. S., at 618. But they are performing important educational services in schools in which education is an integral part of the dominant sectarian mission and in which an atmosphere dedicated to the advancement of religious belief is constantly maintained. See id., at 618-619. The potential for impermissible fostering of religion under these circumstances, although somewhat reduced, is nonetheless present. To be certain that auxiliary teachers remain religiously neutral, as the Constitution demands, the State would have to impose limitations on the activities of auxiliary personnel and then engage, in some form of continuing surveillance to ensure that those restrictions were being followed.
In addition, Act 194, like the statutes considered in Lemon v. Kurtzman, supra, and Committee for Public Education & Religious Liberty v. Nyquist, supra, creates a serious potential for divisive conflict over the issue of aid to religion — “entanglement in the broader sense of continuing political strife.” Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S., at 794. The recurrent nature of the appropriation process guarantees annual reconsideration of Act 194 and the prospect of repeated confrontation between proponents and opponents of the auxiliary-services program. The Act thus provides successive opportunities for political fragmentation and division along religious lines, one of the principal evils against, which the Establishment Clause was intended to protect. See Lemon v. Kurtzman, 403 U. S., at 622-623. This potential for political entanglement, together with the administrative entanglement which would be necessary to ensure that auxiliary-services personnel remain strictly neutral and nonideological when functioning in church-related schools, compels, the conclusion that Act 194 violates the constitutional prohibition against laws “respecting an establishment of religion.”
The judgment of the District Court as to Act 194 is reversed; its judgment as to the textbook provisions of Act 195 is affirmed, but as to that Act’s other provisions now before us its judgment is reversed.
It is so ordered.
See Act 194, § 1 (a), Pa. Stat. Ann., Tit. 24, §9-972 (a); Act 195, §1 (a), Pa. Stat. Ann., Tit. 24, §9-972 (a).
Act 194 provides:
“(a) Legislative Finding; Declaration of Policy. The welfare of the Commonwealth requires that the present and future generations of school age children be assured ample opportunity to develop to the fullest their intellectual capacities. To further this objective, the Commonwealth provides, through tax funds of the Commonwealth, auxiliary services free of charge to children attending public schools within the Commonwealth. Approximately one quarter of all children in the Commonwealth, in compliance with the compulsory attendance provisions of this act, attend nonpublic schools. Although their parents are taxpayers of the Commonwealth, these children do not receive auxiliary services from the Commonwealth. It is the intent of the General Assembly by this enactment to assure the providing of such auxiliary services in such a manner that every school child in the Commonwealth will equitably share in the benefits thereof.
“(b) Definitions. The following terms, whenever used or referred to in this section, shall have the following meanings, except in those circumstances where the context clearly indicates otherwise:
“ ‘Nonpublic school’ means any school, other than a public school within the Commonwealth of Pennsylvania, wherein a resident of the Commonwealth may legally fulfill the compulsory school attendance requirements of this act and which meet the requirements of Title VI of the Civil Rights Act of 1964 (Public Law 88-352).
“ ‘Auxiliary services’ means guidance, counseling and testing services; psychological services; services for exceptional children; remedial and therapeutic services; speech and hearing services; services for the improvement of the educationally disadvantaged (such as, but not limited to, teaching English as a second language), and such other secular, neutral, non-ideological services as are of benefit to nonpublic school children and are presently or hereafter provided for public school children of the Commonwealth.
"(c) Provision of Services. Pursuant to rules and regulations established by the secretary, each intermediate unit shall provide auxiliary services to all children who are enrolled in grades kindergarten through twelve in nonpublic schools wherein the requirements of the compulsory attendance provisions of this act may be met and which are located within the area served by the intermediate unit, such auxiliary services to be provided in their respective schools. The secretary shall each year apportion to each intermediate unit an amount equal to the cost of providing such services but in no case shall' the amount apportioned be in excess of thirty dollars ($30) per pupil enrolled in nonpublic schools within the area served by the intermediate unit.” .
The Pennsylvania Public School Code of 1949 provides that the requirements of the compulsory-attendance law may be met at a nonpublic school so long as "the subjects and activities prescribed by the standards of the State Board of Education are taught in the English language.” Pa. Stat. Ann., Tit. 24, § 13-1327.
The sections of Act 195 relating to the loan of textbooks provide:
“(b) Definitions. . . . ‘Textbooks’ means books, reusable workbooks, or manuals, whether bound or in looseleaf form, intended for use as a principal source of study material for a given class or group of students, a copy of which is expected to be available for the individual use of each pupil in such class or group. Such textbooks shall be textbooks'which are acceptable for use in any public, elementary, or secondary school of the Commonwealth.
"(c) Loan of Textbooks. The Secretary of Education directly, or through the intermediate units, shall have the power and duty to purchase textbooks and, upon individual request, to loan them to all children residing in the Commonwealth who are enrolled in grades kindergarten through twelve of a nonpublic school wherein the requirements of the compulsory attendance provisions of this act may be met. Such textbooks shall be loaned free to such children subject to such rules and regulations as may be prescribed by the Secretary of Education.
“(d) Purchase of Books. The secretary shall not be required to purchase or otherwise acquire textbooks, pursuant to this section, the total cost of which, in any school year, shall exceed an amount equal to ten dollars ($10) multiplied by the number of children residing in the Commonwealth who on the first day of October of such school year are enrolled in grades kindergarten through twelve of a nonpublic school within the Commonwealth in which the requirements of the compulsory attendance provisions of this act may be met.” .
The sections of Act 195 relating to the direct loan of instructional material and equipment provide:
"(b) Definitions.... ‘Instructional equipment’ means instructional equipment, other than fixtures annexed to and forming part of the real estate, which is suitable for and to be used by children and/or teachers. The term includes but is not limited to projection equipment, recording equipment, laboratory equipment, and any other educational secular, neutral, non-ideological equipment as may be of benefit to the instruction of nonpublic school children.and are presently or hereafter provided for public school children of the Commonwealth.
“‘Instructional materials' means books, periodicals, documents, pamphlets, photographs, reproductions, pictorial or graphic works, musical scores, maps, charts, globes, sound recordings,- including but not limited to those on discs and tapes, processed slides, transparencies, films, filmstrips, kinescopes, and video tapes, or any other printed and published materials of a similar nature made by any method now developed or hereafter to be developed. The term includes such other secular, neutral, non-ideological materials as are of benefit to the instruction of nonpublic school children and are presently or hereafter provided for public school children of the Commonwealth.
“(e) Purchase of Instructional Materials and Equipment. Pursuant to requests from the appropriate nonpublic school official on behalf of nonpublic school pupils, the Secretary of Education shall have the power and duty to purchase directly, or through the intermediate units, or otherwise acquire, and to loan to such nonpublic schools, instructional materials and equipment, useful to the education of such children, the total cost of which, in any school year, shall be an amount equal to but not more than twenty-five dollars ($25) multiplied by the number of children residing in the Commonwealth who on the first day of October of such school year, are enrolled in grades kindergarten through twelve of a nonpublic school in which the requirements of the compulsory attendance provisions of this act may be met.”
The individual plaintiffs are Sylvia Meek, Bertha G. Myers, and Charles A. Weatherley; all are resident taxpayers of the Commonwealth of Pennsylvania. The organizational plaintiffs are the American Civil Liberties Union, the National Association for the Advancement of Colored People, the Pennsylvania Jewish Community Relations Council, and Americans United for Separation of Church and State; each group has members who are taxpayers of Pennsylvania. 374 F. Supp. 639, 643. The District Court properly concluded that both the individual and the organizational plaintiffs had standing to bring this challenge to Acts 194 and 195. 374 F. Supp., at 647; see Flast v. Cohen, 392 U. S. 83; Sierra Club v. Morton, 405 U. S. 727.
The original defendants were John C. Pittenger, Secretary of Education of Pennsylvania, and Grace M. Sloan, Treasurer of Pennsylvania. A number of additional parties were permitted by the District Court to intervene as defendants. Some of the individual interveners are parents of children attending nonpublic, nonsectarian schools, who receive benefits under the challenged Acts either directly or through their schools; others are the parents of children attending nonpublic, church-related schools, who are benefited directly or indirectly by the Acts. One organizational intervenor is an association of nonpublic, nonsectarian schools; the other organizational intervenor is a nonpublic, nonsectarian school. 374 F. Supp., at 643.
The appellants had alleged in their complaint that the statutes violate the Free Exercise Clause, as well as the Establishment Clause, arguing that compulsory taxation for the support of religious schools interfered with the free exercise of religion. The District Court held that “the impact of whatever min[u]scule burden of taxation which results to [the appellants] from the expenditures in question has no effect upon the free exercise of their religion.” Id., at 662. Judge Higginbotham, who concurred in part and dissented in part, did not reach the free exercise question. See id., at 680. The appellants have not renewed their free exercise challenge in this Court. Nor have the appellees sought review of that segment of the District Court order invalidating so much of Act 195 as authorized loans of instructional equipment capable of being diverted to religious purposes. Consequently, neither of those issues is now before us.
New York in a single statute authorized the loan of textbooks without charge to students attending both public and nonpublic schools. N. Y. Educ. Law § 701; see Board of Education v. Allen, 392 U. S. 236, 239. The Pennsylvania General Assembly has used two separate provisions of the Public School Code of 1949 to accomplish the same result. Pennsylvania Stat. Ann., Tit. 24, § 8-801, requires that textbooks be provided free of charge for use in the Pennsylvania public schools. Act 195, Pa. Stat. Ann., Tit. 24, § 9-972, provides the authorization for the loan of textbooks to nonpublic elementary and secondary school students. So long as the textbook loan program includes all schoolchildren, those in public as well as those in private schools, it is of no constitutional significance whether the general program is codified in one statute or two. See Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S. 756, 782 n. 38.
Under both the Pennsylvania and New York textbook programs the nonpublic schools are permitted to store on their premises the textbooks being lent to the students. Compare Department of Education, Commonwealth of Pennsylvania, Guidelines for the Administration of Acts 194 and 195, § 4.6, with Board of Education v. Allen, supra, at 244 n. 6.
In Pennsylvania, as in New York, prior to commencement of the state-supported textbook loan program, the parents of nonpublic school children had to purchase their own textbooks. See 374 F. Supp., at 671 n. 11 (opinion of Higginbotham, J.).
Indeed, under the statutory scheme approved in Allen, the books lent to nonpublic school students might never in fact have been approved for use in any public school of the State. The statute permitted the loan of boohs initially selected for use by the nonpublic schools themselves, subject only to subsequent approval by "any boards of education.” See Board of Education v. Allen, supra, at 269-272 (Fortas, J., dissenting). In contrast, only those books which have the antecedent approval of Pennsylvania school officials qualify for loans under Act 195. 374 F. Supp., at 658.
The New Jersey textbook provisions invalidated in Public Funds for Public Schools v. Marburger, 358 F. Supp. 29, aff'd, 417 U. S. 961, unlike the New York textbook program involved in Allen and the Pennsylvania program now before us, were not designed to extend to all schoolchildren of the State, whether attending public or nonpublic schools, the benefits of state-loaned textbooks. Although New Jersey public school children were lent their textbooks, § 5 of the.Nonpublic Elementary and Secondary Education Act, challenged in Marburger, provided that the State Commissioner of Education would reimburse the parents of nonpublic schoolchildren for money spent to purchase secular, nonideological textbooks. The District Court based its decision that the textbook provisions violated the constitutional prohibition against laws "respecting an establishment of religion” on the fact that the assistance provided — reimbursement for purchased textbooks — was not extended to parents of all students, but rather was directed exclusively to parents whose children were enrolled in nonpublic, primarily religious schools. 358 F. Supp., at 36.
Because we have concluded that the direct loan of instructional material and equipment to church-related schools has the impermissible effect of advancing religion, there is no need to consider whether such aid would result in excessive entanglement of the Commonwealth with religion through “comprehensive, discriminating, and continuing state surveillance.” Lemon v. Kurtzman, 403 U. S. 602, 619.
In Lemon v. Kurtzman, supra, at 610, this Court found that 96% of the nonpublic elementary and secondary school students in Pennsylvania in 1969 attended church-related schools. See also Sloan v. Lemon, 413 U. S. 825, 830.
An additional $4,670,000 was appropriated in the 1972-1973 school year for the acquisition of textbooks for loan to nonpublic school students pursuant to Act 195. The total 1972-1973 appropriation under Act 195 was $16,660,000. The appropriation was increased by $900,000 to $17,560,000 for the 1973-1974 school year.
The potentially divisive political effect of aid programs like Act 195, which are dependent on continuing annual appropriations and which generate increasing demands as costs and population grow, was emphasized by this Court in Lemon v. Kurtzman, supra, at 622-624, and Committee for Public Education & Religious Liberty v. Nyquist, 413 U. S., at 794-798. “[Wjhile the prospect of such divisiveness may not alone warrant the invalidation of state laws that otherwise survive the careful scrutiny required by the decisions of this Court, it is certainly a 'warning signal’ not to be ignored.” Id., at 797-798.
Our conclusion that Act 195’s instructional-material and equipment-loan provisions are unconstitutional is directly supported, if not compelled, by this Court’s affirmance last Term of Public Funds for Public Schools v. Marburger, 358 F. Supp. 29, aff’d, 417 U. S. 961. The Marburger District Court invalidated as violating the constitutional prohibition against establishment of religion New Jersey’s provision of instructional material and equipment to nonpublic elementary and secondary schools. New Jersey’s program did not differ in any material respect from the loan provisions of Act 195. See 358 F. Supp., at 36-37. After finding that the nonpublic schools aided, for the most part, were church-related or religiously affiliated educational institutions, id., at 34, the court held that the program had a primary effect of advancing religion. Id., at 37. The court also held, as did the District Court in the ease before us, that excessive entanglement of church and state would result from attempts to police use of material and equipment that were readily divertible to religious uses. Id., at 38-39. This Court’s affirmance of the result in Mar-burger was a decision on the merits, entitled to precedential weight. See Edelman v. Jordan, 415 U. S. 651, 670-671; cf. Cincinnati, N. O. & T. P. R. Co. v. United States, 400 U. S. 932, 935 (White, J., dissenting from summary affirmance).
The appellants do not challenge, and we do not question, the authority of the Pennsylvania General Assembly to make free auxiliary services available to- all students in the Commonwealth, including those who attend church-related schools. Contrary to the argument advanced in a separate opinion filed today, therefore, this case presents no question whether “the Constitution permits the States to give special assistance to some of its children whose handicaps prevent their deriving the benefit normally anticipated from the education required to become a productive member of society and, at the same time, to deny those benefits to other children only became they attend a Lutheran, Catholic, or other church-sponsored school Post, at 386-387.
Because Acts 194 and 195 impose identical qualification requirements, compare Act 194, § 1 (c), Pa. Stat. Ann., Tit. 24, § 9-972 (c), with Act 195, §§ 1 (c), (e), Pa. Stat. Ann., Tit. 24, §§ 9-972 (c), (e), the same schools are eligible for aid under each Act.
More than $14 million was appropriated in the 1972-1973 school year to provide auxiliary services for nonpublic school students pursuant to Act 194. The amount was increased to $17,880,000 for the 1973-1974 school year.
In addition to invalidating New Jersey’s provision of instructional material and equipment to nonpublic schools, see n. 16, supra, the District Court in Marburger struck down the State’s program to supply nonpublic schools with “auxiliary services.” New Jersey defined “auxiliary services” in substantially the same manner ás Pennsylvania, and the administration of the New Jersey program did not differ significantly from the administration of Act 194. See 358 F. Supp., at 39. The District Court held that the auxiliary services program “is unconstitutional by reason of the church-state administrative entanglement it would produce.” Id., at 40. This Court’s affirmance of Marburger is a decision on the merits as to the constitutionality of New Jersey’s auxiliary-services program, and is entitled to precedential weight.
The “speech and hearing services” authorized by Act 194, at least to the extent such services are diagnostic, seem to fall within that class of general welfare services for children that may be provided by the State regardless of the incidental benefit that accrues to church-related schools. See, e. g., Everson v. Board of Education, 330 U. S. 1. Although the Act contains a severability clause, Act 194, § 2, in view of the fact that speech and hearing services constitute a minor portion of the “auxiliary services” authorized by the Act, we cannot assume that the Pennsylvania General Assembly would have passed the law solely to provide such aid. See Sloan v. Lemon, 413 U. S., at 833-834. Indeed, none of the appellees has suggested that the sever-ability clause be utilized to save any portion of Act 194 in the event this Court finds the major substance of the Act constitutionally invalid.
The presence of auxiliary teachers in church-related schools, moreover, has the potential for provoking controversy between the Commonwealth and religious authorities over the extent of the teachers’ responsibilities and the meaning of the legislative and administrative restrictions on the content of their instruction. See Lemon v. Kurtzman, 403 U. S., at 619.