The mixing of government and religion can be a threat to free government, even if no one is forced to participate.... When the government puts its imprimatur on a particular religion, it conveys a message of exclusion to all those who do not adhere to the favored beliefs. A government cannot be premised on the belief that all persons are created equal when it asserts that God prefers some.

By placing discretion in the hands of an official to grant or deny a license, such a statute creates a threat of censorship that by its very existence chills free speech.

Of one thing, however, I am certain. Just as an execution without adequate safeguards is unacceptable, so too is an execution when the condemned prisoner can prove that he is innocent. The execution of a person who can show that he is innocent comes perilously close to simple murder.

If [a United States Supreme Court Justice is] in the doghouse with the Chief [Justice], he gets the crud. He gets the tax cases.

Over our history there are always those who want to take this wall of separation and remove a brick here or there or damage it more than that. I think one has to be vigilant and constantly on the alert.

From this day forward, I no longer shall tinker with the machinery of death.

This Court repeatedly has recognized that the whole subject of the domestic relations of husband and wife belongs to the laws of the States and not to the laws of the United States.