ASHINGTON, Oct. 14 — The Supreme Court added the Pledge of Allegiance to the docket for its new term on Tuesday, agreeing to consider whether public schools violate the Constitution by requiring teachers to lead their classes in pledging allegiance to the flag of "one nation under God."

The justices, who begin their daily sessions with heads bowed as the marshal intones "God save the United States and this honorable court," accepted a case that, like the affirmative action and gay rights cases of the last term, places the court at the center of a public controversy. Justice Antonin Scalia, who has made clear his view that the pledge is constitutional, will not participate, raising the possibility of a 4-to-4 tie.

In another case, the court let stand an appeals court ruling that allows doctors to recommend marijuana as a treatment.

The Pledge of Allegiance case is an appeal by a California school district of a decision that has been the subject of an intense national debate since the United States Court of Appeals for the Ninth Circuit, in San Francisco, issued it 16 months ago.

Of the country's current church-state controversies, including public subsidies for religious education in college, which the court will address in an argument scheduled for December, only the debate over the public display of the Ten Commandments has generated equivalent passion. The justices have so far sidestepped the current round of Ten Commandments cases. The Pledge of Allegiance case will be argued in February or March and decided by early next summer.

The Federal District Court in Sacramento initially dismissed a lawsuit brought by Michael A. Newdow, an atheist who said he did not want his daughter exposed daily in her elementary school classroom to "a ritual proclaiming that there is a God." The Ninth Circuit overturned that decision, ruling in June 2002 that the words "under God," added by federal statute in 1954, made the pledge itself unconstitutional.

In an amended opinion issued this year, the court narrowed its ruling by confining it to the public school context, invalidating school policies that required teachers to lead willing students in the pledge.

Ever since a Supreme Court decision on behalf of Jehovah's Witnesses in 1943, public schools may not compel students to recite the pledge. The Supreme Court indicated on Tuesday that it would address only the public school question, not the constitutionality of the pledge as a general matter.

The Supreme Court's action on Tuesday had several unusual elements that could affect the outcome. One was the decision by Justice Scalia not to participate in the case, an evident if unacknowledged response to a "suggestion for recusal of Justice Scalia" that Mr. Newdow sent to the court last month.

Mr. Newdow cited news reports of remarks the justice made at an event in Fredericksburg, Va., last January that was cosponsored by the Knights of Columbus, the Catholic organization that a half century ago played a leading role in persuading Congress to add "under God" to the pledge. According to the reports, Justice Scalia's speech at an event for Religious Freedom Day pointed to the Ninth Circuit's decision in this case as an example of how courts were misinterpreting the Constitution to "exclude God from the public forums and from political life."

Mr. Newdow, a lawyer and medical doctor who has represented himself in the litigation, told the court that the remarks indicated that Justice Scalia was not just expressing general views on the Constitution but had formed a conclusion about the case itself, providing grounds for disqualification. The code of judicial conduct and a federal law that incorporates it provide that judges "shall disqualify" themselves in cases where their "impartiality might reasonably be questioned."

These provisions do not technically apply to Supreme Court justices, but the justices adhere to them and recuse themselves from cases with which they have connections through stock holdings or personal associations. It is extremely unusual, however, for a recusal to be sought or granted on the basis of a public statement of opinion on the legal issue before the court. Justice Scalia's remarks were consistent with his often-stated views and were surprising only in their specific reference to the case, which had not yet been appealed to the Supreme Court. If a 4-to-4 tie results from his absence, the appeals court's ruling would automatically be affirmed.

Another unusual aspect of the court's order on Tuesday was the suggestion that, in the end, this case might not be suitable for decision. The court instructed the parties to discuss whether Mr. Newdow has standing to challenge the policy of his daughter's public school district, Elk Grove Unified, near Sacramento. The 9-year-old's mother, who has custody and to whom Mr. Newdow was never married, told the appeals court that she not only did not object to the pledge, but also wanted her daughter to recite it "as it stands as part of her education."

The Elk Grove district and the Bush administration, which separately appealed the Ninth Circuit's ruling, challenged Mr. Newdow's standing, as a noncustodial parent, to have anything to do with his daughter's education and told the justices they could vacate the Ninth Circuit's decision on that basis. While the case was waiting for the justices to act, Mr. Newdow informed the court that he had obtained a modified custody order that clarified his rights. Rather than act on the basis of incomplete information, the justices ordered briefing and argument on the issue.

The court turned down a separate petition that Mr. Newdow had filed to seek a broader ruling on the constitutionality of the pledge in general. The court also turned down the Bush administration's appeal, instead inviting the administration to express its views by filing a brief in the school district's case, Elk Grove Unified School District v. Newdow, No. 02-1624.

Analytically, the case is likely to turn on what, in the court's view, the act of reciting the Pledge of Allegiance signifies. The Ninth Circuit majority agreed with Mr. Newdow that the phrase "under God" made the pledge "a profession of a religious belief, namely, a belief in monotheism." In the dissenters' view, reciting the pledge is a patriotic rather than a religious act, analogous to singing the national anthem. All 50 states urged the court to hear the appeal. Nearly all the states either authorize or require recitation of the pledge in their public schools.