The Political Origins of Secular Public Education: The New York School Controversy, 1840-1842
[A] compulsory state educational system so structures a child's life that if religious exercises are held to be an impermissible activity in schools, religion is placed at an artificial and state-created disadvantage. [The] refusal to permit religious exercises thus is seen, not as the realization of state neutrality, but rather as the establishment of a religion of secularism.
Justice Potter Stewart, dissenting
School District of Abington v. Schempp
374 U.S. 203, 313 (1963)
Designed to serve as perhaps the most powerful agency for promoting cohesion among a heterogeneous democratic people, the public school must keep scrupulously free from entanglement in the strife of sects. The 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.
Justice Felix Frankfurter, concurring
McCollum v. Board of Education
333 U.S. 203, 216-31 (1948)