What to Know About Religious Beliefs in the Classroom
This article was originally published by Freedom Forum
Among 2025’s marquee U.S. Supreme Court cases was Mahmoud v. Taylor, in which a group of Maryland parents claimed a First Amendment right to opt their children out of certain LGBTQ+-inclusive readings in local public school classrooms. The parents argued that mandatory exposure to the books’ themes, which contradicted their religious beliefs, undermined their First Amendment right to direct their children’s religious upbringing. The court ultimately ruled in favor of the parents, saying that the schools’ lack of an opt-out option interfered with the parents’ right to the free exercise of religion.
While the case did not deal with the teaching of science, it has much in common with a long history of parents’ concerns about public school science curricula and health classes that conflict with their religious beliefs.
This article explores these teachings that may conflict with religious beliefs and how the First Amendment comes into play. It also discusses key court cases on this issue.
Science and religion in public schools
In public schools, the kinds of topics that may relate to and conflict with religious beliefs have often involved teachings or practices that include:
- The origins and history of Earth and life, such as the teaching of evolution versus creation science and intelligent design
- Sex education
- Health practices, such as school policies regarding vaccines
Parents who see these teachings and practices as conflicting with their religious beliefs may sometimes seek changes or exceptions to those curricula or practices. These requests may take several forms, whether by asking to opt children out of objectionable classes or school requirements or, more broadly, by asking that schools not teach the objectionable material at all or even teach religious perspectives instead of or in addition to scientific theories.
What have courts said about the conflict between religion and science teachings in public schools?
The primary lens through which courts view these conflicts are the two religion clauses of the First Amendment:
- The establishment clause prevents government from either advancing (that is, establishing) or hindering religion, preferring one religion over others, or favoring religion over nonreligion.
- The free exercise clause protects the right of individuals and groups to practice their religion openly and freely without governmental interference.
Courts have consistently held that the First Amendment requires public schools to teach and act on the basis of evidence-backed scientific concepts, not religious doctrine. Moreover, courts have said that there is no obligation for a school to “teach the controversy” if no scientific controversy exists, for example, referencing the arguments for creationism when teaching evolution. Although teachers can teach about these subjects — such as by including them in a segment on comparative religious perspectives — as long as they don’t teach them as scientific fact.
Importantly, however, the law also requires public schools to maintain a neutral stance toward religion — that is, ensuring they don’t disparage or promote particular religions or religious views. Nor are students obligated to agree with everything they hear and are free to ask questions and to express their own religious views, whether in class or in completing class assignments — within the constraints of due respect for and relevance to the subject. Importantly, teachers can require students to select test answers based on the curriculum, even where it might conflict with a students’ personal religious beliefs.
An early prominent case on the conflict between religion and science in the classroom occurred at a time when modern-day understandings of the religion clauses had not yet developed: the 1925 Scopes Monkey Trial. High school teacher John Scopes was accused of violating a Tennessee state law that criminalized the teaching of human evolution in public schools. The American Civil Liberties Union represented Scopes at trial, taking the case for the express purpose of challenging the constitutionality of the law.
The Tennessee trial court convicted Scopes in July 1925. Eighteen months later, in January 1927, the Tennessee Supreme Court overturned the verdict on appeal, but on the grounds that the underlying statute was too vague to be enforceable, as opposed to claims based on free speech or the Tennessee Constitution’s prohibition of government establishment of religion.
A note on the establishment clause in the states
In 1925, the U.S. Supreme Court had not yet found that the establishment clause applies to the states — only to the federal government. Any no-establishment argument had to be based on the state’s — in the Scopes case, Tennessee’s — constitution.
The Supreme Court wouldn’t extend the establishment clause to the states until 1947 (Everson v. Board of Education).
It wasn’t until some 40 years later that the U.S. Supreme Court struck down a law forbidding the teaching of evolution in public schools. The court reasoned that the law violated the establishment clause of the First Amendment because it was based solely on the belief that the theory of evolution contradicted a particular interpretation of the Book of Genesis (Epperson v. Arkansas, 1968).
Following that decision, the court struck down a law requiring schools to teach “creation science” if they also taught evolutionary science, and vice versa (Edwards v. Aguillard, 1987). The court said creation science was a fundamentally religious concept and that teaching it as science in public school would amount to government establishment of religion.
Then, in 2005, a U.S. District Court in Pennsylvania extended this analysis to a policy requiring the teaching of intelligent design in public schools (Kitzmiller v. Dover Area School District). The court ruled that intelligent design was also rooted in religious doctrine and that presenting it as science in public schools would similarly violate the establishment clause.
How do these cases extend to health and sex education in public schools?
These court decisions apply not only in the context of a science class, but in other situations as well, such as teaching about human reproduction and sexual health.
Beginning around 1970, parents started to bring constitutional challenges to the growing practice of including sex education in school curricula.
Following the Supreme Court’s 1987 decision in Edwards v. Aguillard that teaching a fundamentally religious concept as science in public school amounts to government establishment of religion, courts are unlikely to direct schools to revise health and sex education curricula to meet religious objections.
However, in light of parents’ constitutional right to govern the “education of children under their control,” which the court confirmed in this year’s Mahmoud v. Taylor decision, schools must seriously consider parents’ religious opt-out requests — subject to the weighing of other important state interests. Indeed, as of the beginning of 2025, some 42 states have policies in place allowing parents to opt out of sex education for their children.
The bottom line on religion and science in schools
The First Amendment has operated not to silence religious voices and practices but to protect them. At the same time, it works to ensure public schools do not promote certain religious traditions and beliefs over others. Taken together, that is the true meaning of government neutrality toward religion.
Richard Foltin is a fellow for religious freedom at Freedom Forum. He can be reached at media@freedomforum.org.
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- Faith, Science and the First Amendment – by Richard Foltin - October 30, 2025