". . . No man shall be compelled to frequent or support any religious worship, place, or ministry whatsoever, nor shall be enforced, restrained, molested, or burthened in his body or goods . . . but that all men shall be free to profess and by argument to maintain their opinion in matters of religion . . . . "

It will have been 200 years in January since the General Assembly of Virginia adopted Thomas Jefferson's revolutionary notion, summed up in that key passage from his statute on religious freedom.

Accordingly, this week some 150 scholars gathered at the University of Virginia here to celebrate Jefferson's invention, which quickly found its way into the U.S. Constitution.

They examined applications of the idea over the last two centuries and added to the increasing debate over how the religious freedom statute should be applied today.

Contemporary Americans may take for granted their right to participate in any religion or none, but it was not always so.

In Virginia, Anglicanism was the established church. Although, as one of the speakers here pointed out, "it was not exactly thriving," especially after the Revolutionary War when the priests who had supported the British had fled back to England, it had the power of the state on its side.

Only Anglican clergymen could legally perform marriages and baptisms, noted David Little of the University of Virginia.

"Dissenters, such as the Baptists and Presbyterians, whose ranks were rapidly expanding, were refused admission to municipal and business corporations, were prevented from holding civil and military offices, and were excluded from the universities," he said in a paper prepared for delivery this morning.

And each of the other 13 colonies, except for Rhode Island and Pennsylvania, had some form of established religion.

After all, the European nations from which the early settlers came all had their established churches, in some instances controlling as much as 60 percent of the nation's land and wealth, said Harry J. Abraham of the University of Virginia.

So it is not surprising that it took Jefferson nearly a decade between the time he first proposed his religious freedom idea and its adoption by the Virginia legislators.

Two hundred years later, Martin E. Marty of the University of Chicago said, the Jeffersonian concept of religious freedom is "on the defensive."

In the largest public session of the three-day conference held on the campus that Jefferson designed, Marty called the religious freedom statute "the most decisive element in an epochal shift in the Western World's approach to relations between civil and religious spheres of life after 14 centuries."

Even though the Jeffersonian concept of religious freedom was incorporated in the First Amendment to the U.S. Constitution, it was only in the last four or five decades that "First Amendment provisions began to be applied to all the states," Marty said.

The first Supreme Court decision that started the modern practice of making decisions about religion on the basis of the First Amendment came in 1940, Marty noted.

In recent years, the high court docket has been increasingly laden with a range of church-state issues.

At the same time, the University of Chicago historian said, "Some organized forces in American Protestantism have tried to defederalize the First Amendment religion clauses to turn back to the states the powers to determine legal matters concerning religion."

More recently those "forces" -- primarily right-wing evangelicals -- have been joined by such high government officials as Attorney General Edwin Meese, who "very strenuously called into question" last summer the Supreme Court's reasoning on church-state separation cases.

The Rev. Robert Drinan took sharp issue with the Supreme Court's interpretation of the First Amendment in repeatedly rejecting aid to church schools, particularly the Title I program of aid to disadvantaged children, which the court ruled unconstitutional this year.

Catholics are currently in an "awkward" position in their quest for school aid because "now we have new friends that we didn't seek . . . including Jerry Falwell and, so help me, the Republican Party," said the one-time Democratic U.S. representative from Massachusetts and national head of Americans for Democratic Action.

He challenged the finding by the majority of the court that the Title I program involved "excessive entanglement" of the government with religion.

The nation's 52 million Catholics are caught in a bind by contemporary interpretations of the First Amendment, which was drafted when the Catholic Church "hardly existed either in Virginia or in the other colonies."

The continued rejection of all forms of aid to parochial schools, which educate about one third of all Catholic children, leads "many, not all," Catholics to feel they "have not been helped by an approach to church-state relations which might have been acceptable to America in the year 1800 but is not fair or equitable in the year 1985." Drinan said.

"But it is awkward for Catholics to argue this way. However firmly a Catholic may believe in the justice of some governmental assistance to Catholic schools, it is difficult to speak out when on the other side there is arrayed the National Council of Churches, the American Civil Liberties Union, the National Education Association and 40 years of decisions by the Supreme Court."

Drinan asserted that "no other nation denies aid to religious schools."

In the question period, Drinan rejected as a proposed solution the so-called voucher system, in which every child is allotted a fixed sum for schooling, with no stipulations as to enrollment.

"I am a great advocate of public schools," he said, "and I don't want to see them weakened," as many experts predict would be the result of the voucher system.