"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances."

I. Theories

Neutrality (formal): The theory that the government should be blind to religious differences. Religion may not be used as a basis for classification for purposes of governmental action, whether that action be the conferring of rights or privileges or the imposition of duties or obligations. A formally neutral law applies equally to religious institutions and secular institutions, and it applies equally to the same conduct whether that conduct was done for religious reasons or secular reasons.

Neutrality (substantive): The idea that the government should neither encourage nor discourage religious belief or practice. Supporters of substantive neutrality believe that, sometimes, neutrality requires government to take account of religious differences.

Secularism: Secularists believe that the obligations to create a secular culture of liberal democracy means that no faith can be translated into public policy, although religious voices can participate in the democratic system. The Establishment Clause, under the secularism theory, will prohibit the government from approving anything religious, including practices that the Supreme Court has claimed only acknowledge religion, such as legislative prayer.

Separationism: The belief that religion clauses ban any government aid to religious organizations, even when it is based on neutral criteria. Separationists, generally called "Strict Separationists," adhere to Thomas Jefferson's metaphor of a "wall of separation between church and state." Separationists believe that religion should be completely separate from public life.

Non-preferentialism: The theory that the Framers of the Constitution meant to forbid government action that prefers one religious sect over another, but not action that prefers religion in general over non-religion.

Accommodation (pluralism): The notion that the primary purpose of the religion clauses of the First Amendment is to protect the U.S.'s pluralistic religious heritage. Government should therefore accommodate religion whenever possible. Whenever government supports a secular institution, such as public schools, it should also equivalently support religious parochial schools. The government, instead of taking down religious symbols, should erect more religious symbols to reflect the diversity of religions in America.

Anti-Secularism: The belief that the roots of American law are explicitly religious, that the Framers were religious men who never intended the total separation of church and state, and that the current secular legal order has unconstitutionally established secular humanism, a nontheistic religion that worships humankind as the source of meaning.

II. Supreme Court Tests

Lemon Test: From the 1971 Supreme Court decision in Lemon v. Kurtzman, in which the Court struck down a state program providing financial aid to religious elementary and secondary schools. The Court said that for a statute to comply with the Establishment Clause, three things must be true:

1. the statute must have a secular legislative purpose
2. its principal or primary effect must be one that neither advances nor inhibits religion
3. the statute must not foster "an excessive government entanglement with religion"

Lemon Test redux: From the 1997 Supreme Court decision in Agostini v. Felton, in which the Court held that allowing public school teachers to teach in parochial schools does not violate the Establishment Clause. The Court identified three primary criteria for determining that government aid has a primary effect of advancing religion:

1. The aid results in governmental indoctrination
2. The aid program defines its recipients by reference to religion
3. The aid creates an excessive entanglement between government and religion

Coercion Test: Support for the adoption of a test outlined by Justice Anthony Kennedy in his 1989 dissent in County of Allegheny v. ACLU. Believes the government does not violate the establishment clause unless it...

1. provides direct aid to religion in a way that would tend to establish a state church, or
2. coerces people to support or participate in religion against their will.

Endorsement Test: Proposed by Justice Sandra Day O'Connor in the 1984 case of Lynch v. Donnelly. States that a government action is invalid if it creates a perception in the mind of a reasonable observer that the government is either endorsing or disapproving of religion.

Neutrality Test: Cited first as a guiding principle in Everson v. Board of Education, neutrality meant government was neither the ally nor adversary of religion. The government would treat religious groups the same as other similarly situated groups.