In 1980 (Stone v. Graham), a United States Supreme Court decision struck down a Kentucky law requiring that a copy of the Ten Commandments be posted in every public school classroom, the Court saying:
"The pre-eminent purpose for posting the Ten Commandments on schoolroom walls is plainly religious in nature. The Ten Commandments are undeniably a sacred text in the Jewish and Christian faiths, and no legislative recitation of a supposed secular purpose can blind us to that fact. The Commandments do not confine themselves to arguably secular matters, such as honoring one's parents, killing or murder, adultery, stealing, false witness, and covetousness. Rather, the first part of the Commandments concerns the religious duties of believers: worshipping the Lord God alone, avoiding idolatry, not using the Lord's name in vain, and observing the Sabbath Day."
The reasoning shown above was based on the constitutional requirement for separation of church and state. Presumably the Ten Commandments would have been acceptable if texts from the Koran and various other scriptures had been given equal prominence.
