As the Supreme Court has often noted, the two religious clauses in the First Amendment -- the right to free exercise of religion and the command that the state not "establish" or prefer a religion -- often collide. As when a Sabbath-observing Jewish public school student asks that his high school graduation not be held on Saturday. Almost invariably, the school board respectfully but firmly declines to move the date, for such an action would entangle the state with a particular religion.

For the first time, a federal district court has held that it is indeed a violation of the free exercise of religion to refuse to accommodate a Jewish student whose religion mandates that on Saturdays he not attend social events, play any sports, play music, write, turn the electricity on and off or attend a graduation exercise, thereby breaking "the spirit of the Sabbath."

The student in question, 17-year-old David Smith, will be graduated in June 1988 from North Babylon Senior High School on Long Island. The board of education claims that moving the date for Smith "would open the floodgates and interminably entangle the board of education and the courts into determining whether any date could be religiously convenient to all of its students."

Moreover, the school board, taking on the role of a "Bet Din" (a Jewish religious law court), claims to have caught young David in an inconsistency that torpedoes his case. The boy admits to reading his homework assignments on Saturdays, though without the aid of electric light. Those books are secular volumes, and so David himself has violated the Sabbath, says the board.

In his court papers, David -- through his American Jewish Congress attorneys -- points out that he has a resident expert in Jewish law, his father, a rabbi. And he cites other authorities to affirm his right to read books of science and other secular subjects without thereby breaking the law of the Sabbath.

Anyway, federal Judge Jacob Mishler reminded the school board that, as the Supreme Court has emphasized, "religious beliefs need not be acceptable, logical, consistent or comprehensible to others in order to merit First Amendment protection."

Another school board argument was that Saturdays are chosen for "administrative con-venience." For example, fewer teachers would volunteer to help with graduation if it were moved to Sunday. Aside from William O. Douglas' point that "administrative convenience" is of much lesser weight than the Bill of Rights, the fact is that from 1962 to 1971, graduation exer-cises at that school were held on Sunday afternoon. And currently, of 25 public school districts neighboring the North Babylon Union Free School District, 19 hold graduation on Sundays. Those districts do not appear to be experiencing any notable administrative inconvenience.

Mishler ruled, moreover, that although David could get his diploma without attending the exercises, they are an important state benefit, and holding them on a Saturday places "substantial pressure" on David "to modify his behavior and to violate his beliefs" to secure that benefit. Only a compelling state interest would justify such infringement of his First Amendment rights.

There certainly is a compelling state interest, said the school board. If the day is moved to Sunday, other students might interpret the change as showing the board's preference for David's religion. Accordingly, the board would be guilty of undermining the Establishment Clause.

Mishler responded by emphasizing that moving the date would merely show that the school board was being neutral in the face of religious differences. After all, he might have added, continuing to hold the exercises on Saturdays only could be interpreted by Orthodox Jewish public school students as government hostility toward the Jewish religion.

What about the school board's fear that the floodgates will be opened? It is a possibility. If Mishler is upheld -- his summary judgment is being appealed -- the result will apply to any student in any year who gives sufficient advance notice that the graduation day interferes with his or her Sabbath. (The "Sabbath" does not have to be a Saturday.)

Nonetheless, Mishler declared "the fear of 'running afoul of the Establishment Clause' cannot be allowed to prevent granting protection to an adherent whose free exercise rights are threatened."

Constitutional rights cannot be denied on the basis of what may happen sometime in the future. And even then, as Mishler says in his last footnote: "If it should be shown that the religious beliefs of another individual or group would be infringed by a graduation held on another selected day, this, too, may impose an unconstitutional burden on the free exercise of religion." Pluralism can sometimes be inconvenient, but the alternative is stifling.