I admit to a liking for the innovators and the flouters of conventions. Ron Reagan dancing in his underwear and Jim McMahon, the illegally headbanded quarterback, gave me a lift. Still, I come up short when the front-guard thinkers turn God into a woman.

It happened again last week. The Rev. Charles Curran, considered by his peers as American Catholicism's leading moral theologian, said "God is a gracious mother and father of us all." Years are likely to pass before I don't trip over that. Eventually, though, I know I will be saying, yes, Curran has a point. I will be grateful that he brought innovation to theology and said that masculinity and femininity are both compatible with our idea of God.

Slow-on-the-take people like me are the least of Curran's problems. Last week, he revealed that the Vatican has accused him of "errors and ambiguities" in his writings. Curran, who is a tenured professor of moral theology at Catholic University, was charged with a lack of theological conformity on questions of sexual morality, including contraception. In 1968, he was one of a number of theologians who dissented from official church teaching that artificial birth control is morally wrong. Theology, like dancing and football, is an interpretive science. The church, through the Vatican's Sacred Congregation for the Doctrine of the Faith, is a private institution with full rights to assert its demands that no deviancies be allowed, much less taught, at a school like Catholic University. Chartered by Rome, it is akin to being the West Point of American Catholicism. Its marching orders are known to all who join the ranks. Authority, whether clerical or military, is to be obeyed.

That would appear to close the Curran case: The Vatican was within its rights to order, as it did, that one of its theologians "reconsider and retract" his views or else be sent into academic limbo. The trouble is -- and here is where Curran deserves support -- the church may not be a democracy but its policies affect people who are beyond its membership. When Curran argues, as do many other loyal Catholics, that artificial birth control is permissible, he is also talking about overpopulation. That involves everyone on the planet.

It especially involves the world's poorest countries. Last month, Pope John Paul II visited India and told its 746 million inhabitants that the church was unbending in its opposition to artificial birth control. The pope quoted Mahatma Gandhi on birth control, that the "suspension of procreation" should not be accomplished "by immoral and artificial checks . . . but by a life of discipline and self-control." The church's liberal theologians agree that abstinence or natural family planning are the ideal ways to avoid pregnancy, but those aren't the only moral ways.

The church's teaching on sex has been evolving for 20 centuries. It was only in 1274, at the Council of Lyons, that marriage was declared a sacrament. American bishops first discussed contraception in a 1919 pastoral letter. That was three years after Margaret Sanger, a Brooklyn public-health nurse, was arrested for operating a birth-control clinic. Sanger kept at it. Among her more vocal opponents was Cardinal Hayes, the archbishop of New York. A headline in the Nov. 14, 1921, New York Times read: "Birth Control Raid Made by Police on Archbishop's Orders."

Church and state have since parted on the issue, and so now have church and church. In 1968, 600 theologians dissented from Pope Paul VI's 1967 encyclical that upheld the ban on artificial birth control. Charles Curran was dismissed from his teaching the same year, only to be reinstated after a five-day student strike.

Now it's happening again. The Vatican appears to be playing catch-up discipline. Curran hasn't taught sexual ethics for 15 years. Another oddness is that he is known as a careful and scholarly thinker who, compared with other theologians, is a moderate. His statements last week confirm that. Curran argued that he is not challenging the church's infallible teaching on dogma. Instead, his point is that different levels of teaching exist: infallible and fallible. On the second, dissent is normal and often necessary. If it weren't, the church would still be against usury and religious liberty. Catholics would be praying in Latin and eating fish on Fridays.

Theologians from Switzerland and Brazil have been rebuked in recent years by the Vatican of Pope John Paul II. Curran's case is different because of the sex issues. Catholicism, a religion of many strengths and beauties, is a male-controlled organization that appears to be unyielding in opening its official teachings to new interpretations demanded by 20th-century realities. Few institutions should understand the need for openness more clearly. How else did the church survive this long without its gift for prudent flexibility?