The head of the American Catholic hierarchy has rejected the basic premises of a report on a two-year study of human sexuality written by the Catholic theological Society of America.

Archbishop Joseph L. Bernardin, of Cincinnati, president of the American hierarchy, issued a statement yestersay acknowledging that he had "not read this document." but asserting that "there can be little doubt as to what the Church teaches on the question of sexual morality."

He noted that "theologians have a right and duty to seek a deeper understanding of the Church's authentic teaching. But it is in the teaching which is normative, and it is in the light of this teaching that theological speculation is evaluated.

The new study by the society would discard the rigid "thou-shalt-nots" of sex, imposed by the Church over the centuries, and instead encourage the faithful to make their own decisions about right and wrong in the light of firm moral principles applied to individual circumstances.

The 299-page study, entitled "Human Sexuality: New Directions in American Catholic Thought," examines waht the Bible and Christian tradition - as well as secular scientific research - have to say about sex. All this provides the groundwork for a frank and candid consideration of the rights and wrongs of sexual practices ranging from masturbation to transsexualism.

The study was launced by the CTSA because of "the growing gap between what the Catholic Church officially teaches in matters sexual and what the faithful have come to believe and practice," and introductory statement says. A study last year by priest-sociologist Andrew Grelley, for example, disclosed that approximately 80 per cent of American Catholics practice contraception, which is contrary to Church teaching.

Central to the theological task force's way of evaluating sexual morality is the question of "whether specific sexual behaviour realizes certain growth and integration of the human person."

This is in contrast the authors say, to traditional Catholic views of sexual morality that ask "the simple, direct question: 'Is this act moral or immoral?'"

That traditional approach is "flawed in two highly significant ways," the report says, because it overlooks "the complexity of the human moral enterprise" and "it implies a greatly oversimplified understanding of sexuality."

The theologians' report cites seven principles for evaluating sexual behaviour: "Self liberating . . . other-enriching . . . honest . . . faithful . . . socially responsible . . . life-serving . . . joyous."STThese criteria, the authors state, "are not meant to serve as a check list, the full and complete presence of which will guarantee wholesome sexual expression." For fallible humans, such an ideal is not realistic. But, they state, "though each value may not be equally served in any particular sexual expression, the substantial violation of any of these values should raise serious questions about the ability of that sexual expression to enhance creative and integrative growth of the human person.

The section of the study evaluating specific sexual practices devotes 33 pages to consideration of homosexuality - more than to any other individual subject. Although homosexuality is unequivocally condemned by traditional Church teaching, it has become an issue of growing concern in recent years among many Catholic leaders, as it has to some segments of secular culture.

The theologians' report suggest that under certain circumstances, a sexual relationship between homosexuals can be morally justified.

Reflecting throughout the caution with which contemporary theologians tend to approach this subject, the chapter warms against "the danger of being misunderstood, particularly by the careless reader who would open the study at this section without having read the preceding chapters."

The study notes that an estimated 5 per cent of the total population, or about 10 million Americans, "are exclusively homosexual all their sexual lives."

According to the theologians, "homosexuals have the same rights to love, intimacy and relationships as heterosexuals. Like heterosexuals, they are also bound to strive for the same ideals in their ralationships for creativity and integration" - a reference to the study's guiding principle for any sexual action.

The study acknowledges the traditional Church position that homosexual acts are "intrinsically evil" but points aut that for all practical purposes, the Church thus restricts homosexuals to a life of celibacy.

"The homosexual is one for whom an exclusive or predominant homosexual orientation is for all practical purposes natural and irreversible," the study says. "This irreversible condition is no more a matter of free choice for a homosexual than is the orientation of the heterosexual . . .

"Heterosexuals are free to choose or not to choose a life of celibacy. Are homosexuals denied that free choice?" the report asks, and answers: "It is our considered opinion that Christian sexual morality does not require a dual standard. Homosexuals enjoy the same rights and incur the same obligations as the heterosexual majority."

Sex outside of marriage is also dealt with in some detail. The theologians offer little comfort to advocates of free sex, mate swapping or "swinging."

On adultery, the theologians note that any moral assessment "must necessarily consider the effects on at least three people: the marriage partners and the third party . . . In general it seems difficult to imagine a situation where such activity would be considered to be good afor all involved."

The theologians, however, question the church's traditional blanket condemnation of all sex outside marriage.

"There can be no doubt but that the traditional moral code regarding premarital sex is inadequate, particularly in its lack of distinction between the ages, attitudes and intentions of the people involved," the theologians say.

The statement suggests that pre-marital sex between partners with a "serious and growing commitment" toward each other and to marriage might under some circumstances be moral. The theologians warn that "there exists an essential relationship between sex and marriage. Even in the wake of a sexual revolution, it can be maintained and substantiated that marriage is the ideal context for the full human realization and self-communication that is involved in the sexual expression of love."

On sex within marriage, the theologians state: "Moral evaluation of sexual intimacies in marriage requires that they be measured in terms of their ability to foster creative and integrative growth and not in terms of their physical nature. No physical expression of sexuality, including oral sex, provided it be mutually sensitive and acceptable, should be prejudged as morally wrong or perverse."

On contraception: "The mature Catholic acknowledges a responsibility to take into consideration the official teaching of the Church when forming his or her conscience on moral matters."

The theologians also assert that the Church requires responsible parenthood of married couples and "at times, this demands family limitation. Parents themselves are the ultimate decision-makers in this matter."

The study upholds the value of celibacy for persons such as priests and nuns, who opt for it, but warns that such persons "must know how to experience a healthy, affective maturation in their own persons; to give and receive friendship with persons of their own and of the opposite sex; to express 'universal' love in specific concern and care for others; to acknowledge the possibility of a unique, intense, personal encounter that at some moment in their lives invites to an intimate, exclusive, lasting relationship."

The five-person team that developed the report was chaired by the Rev. Anthony Kosnik, dean of Sts. Cyril and Methodius Seminary, Orchard Lake, Mich. Other members were William Carroll, currently professor of law at the John Marshall School of Law, Chicago; Sister Agnes Cunningham, associate professor at St. Mary of the Lake Seminary in Mundelein, III,; the Rev. Ronald Modras, associate professor of systematic theology at St. John's Seminary, Plymouth, Mich., and James Schulte, director of instruction at the St. Joseph's Hospital School of Nursing in Marshfield, Wis.

In a "postscript" to their report, the theologians state: "We have given particular attention to magisterial statements regarding sexuality; but where new knowledge and insights have rendered traditional understanding and formulation inadequate, we have not hesitated to suggest new directions that would be we hope, more useful to present circumstances yet still faithful to the sources of Christian moral guidance.

"We see our efforts as contributing not to dissent but rather development of Church Teaching."