It could be “a mess,” said Justice Stephen Breyer.

That sentiment seemed to sum up the intellectual somersaults performed by the justices of the U.S. Supreme Court on Wednesday, as they grappled with the question of who is a minister and when a minister is exempt from federal laws that apply to everyone else.

The court’s eventual decision will have profound implications for the nation’s religious institutions and the people who work in them.

The case before the court began when Cheryl Perich, a tenured teacher at a parochial school, took disability leave after she was diagnosed with narcolepsy. When her doctor certified that she was ready to return to work, the school asked her to resign, and when she threatened to sue under the Americans with Disabilities Act, she was fired.

The Hosanna-Tabor church and school in Redford, Mich. does not dispute that it fired Perich for threatening to sue. The school maintains that, although Perich taught primarily non-religious subjects like math and science, she is a minister because she taught one religion course. Under church doctrine, ministers are required to resolve all disputes within the church. Thus, the church argues that Perich is exempt from the provisions of the Americans with Disabilities Act and has no right to go to court to win back her job.

But inside the Supreme Court, Douglas Laycock, the school’s lawyer, immediately ran into a buzz saw when Justice Ruth Bader Ginsburg noted that Perich had never been decommissioned as an officer of the church, and the school principal even recommended her to other parishes.

Justice Sonia Sotomayor then turned the questioning to whether religious institutions are immune from lawsuits when they fire a person on the basis of a pretext, asking “How about a teacher who reports sexual abuse to the government and is fired because of that reporting?” Doesn’t society have a right to say certain conduct is unacceptable even when it occurs in a religious institution, she asked.

Observing that Perich was “fired simply for asking for a hearing,” Justice Anthony Kennedy asked whether going through an Equal Employment Opportunity Commission hearing would have settled whether she was actually fired for a religious reason. When Laycock hesitated, Justice Antonin Scalia leaped to the rescue: “I think your point is that it’s — it’s none of the business of the government to decide what the substantial interest of the church is.”

Chief Justice John Roberts sought a concrete definition of who counts as a minister. What about a “teacher who teaches only purely secular subjects, but leads the class in grace before lunch. Is that somebody who would be covered” as a minister? Laycock seemed to say that such a teacher would not be covered.

Roberts did not relent, noting that some churches view all its members as ministers. Laycock replied that, in cases like that the courts might determine how many secular duties the individual performs.

Justice Kennedy, exasperated, said that is exactly the question in Perich’s case.

That prompted Justice Scalia to ask how a minister should be defined. A person is a minister, Laycock replied, if it is “per your job responsibilities to teach the doctrines of the faith.”

Justice Ginsburg, unconvinced, noted that Perich’s “duties at the school, did not change from when she’s a contract teacher, and therefore not a minister” to when she became a commissioned minister. Indeed, Ginsburg continued, the majority of Lutheran teachers are lay ministers and not commissioned.

Returning yet again to Laycock’s definition of minister, Justice Sotomayor seemed to suggest that Laycock’s functionality test, where a minister is “anyone who teaches religion” would include even people who were not members of the faith. Justice Scalia asked Laycock if, “you’d be here anyway even if she hadn’t been ordained,” to which the response was, “yes.”

Defending Perich’s right to sue was the EEOC, represented by Assistant Solicitor General Leondra Kruger. She faced an even tougher battering from the justices after she asserted that Congress was perfectly within its rights in making it illegal to fire a fourth-grade teacher in retaliation for asserting her rights under the disabilities law.

Chief Justice Roberts probed that assertion, asking if “there [is] anything special about the fact that the people involved in this case are part of a religious organization.” The “basic contours,” responded Kruger, “are not different.”

At this, Justice Scalia exploded. “That’s extraordinary,” he proclaimed, noting that the Constitution does not protect, say, labor unions. “But there, black on white in the text of the Constitution are special protections for religion.”

Justice Alito asked whether the constitutional principle of separation of church and state was designed to prevent the government from selecting ministers. “No,” responded Kruger, who also objected to a characterization that anti-discrimination laws in some way amount to “choosing the ministers.”

Following Kruger to the lectern was Perich’s lawyer, Walter Dellinger. He literally got one word out of his mouth before the justices pounced. Justice Elena Kagan asked Dellinger “why this commissioned minister does not count as a minister,” to which he responded that she was not a minister because “she carries out important secular functions in addition to her religious duties.”

Chief Justice Roberts was not persuaded, saying, “The Pope is a head of sate carrying out secular functions.” Is he not a minister? Dellinger rejected Laycock’s “categorical approach” as being both “over and under inclusive.” When a religious organization enters the public arena, as it does when it sets up schools, it is involved with government rules, and those rules have to be applied with neutrality. In other words, there is no automatic exemption for those the church dubs ministers.

Whether the Supreme Court buys that argument remains to be seen.

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