A Vatican document approved by Pope Benedict XVI says that "those who are actively homosexual, have deep-seated homosexual tendencies or support the so-called gay culture" cannot be admitted to seminary or ordained.
The Vatican would not officially confirm or deny the authenticity of the document, but a Vatican official who had seen it, told The Associated Press that it was the final text that had been slated for release next week.
Some conservative Catholics have wanted a document that would ban homosexuals from the seminary, saying they believed there was an actively gay subculture in the priesthood and that gay priests were primarily responsible for the sexual abuse scandal that has rocked the church.
Many moderate and liberal Catholics have predicted that such a statement would drive safely celibate gay priests out of the ministry and have argued that homosexuality is not linked to sexual abuse of minors.
Application of the instruction, as it is termed, is likely to turn on how bishops and seminary rectors define "deep-seated homosexual tendencies," a term not defined in the document itself.
A brief five pages, it opens by reviewing Catholic teaching which says that homosexual acts are "intrinsically immoral," and "deep-seated homosexual tendencies" are "objectively disordered" -- a theological phrase meaning contrary to the way humans were created to behave. But it also says that homosexuals "must be accepted with respect and sensitivity; every sign of unjust discrimination in their regard should be avoided."
The key paragraph states that "the church, even while deeply respecting the persons in question, cannot admit to seminary or holy orders those who are actively homosexual, have deep-seated homosexual tendencies, or support the so-called gay culture."
It makes an exception for "homosexual tendencies that might only be a manifestation of a transitory problem." Such transitory problems must be "clearly overcome" for at least three years before the man can be ordained a deacon, the document says. It does not explain what is meant by "clearly overcoming" a transitory tendency.
Because it was not released by the Vatican, church officials, including Bishop Donald Wuerl of Pittsburgh and the spokesmen for the U.S. Conference of Catholic Bishops, would not comment on it.
This, however, is not new teaching. In 1961, a document on the selection of seminarians said that homosexuals should not be admitted. Although some reports say this document was in the works before 2002, it is widely believed to have been spurred by the scandal of priests who sexually abused minors, most of whom were male. The document says only that its teaching was "made more urgent by the current situation."
Mike Sullivan, a spokesman for Catholics United for the Faith, a lay group dedicated to supporting church teaching, welcomed the instruction.
"If a person has deep-seated homosexual tendencies, then it's going to be difficult, almost impossible, for him to relate the church's teaching on homosexuality in an authentic way," said Mr. Sullivan, of Steubenville, Ohio.
Asked about homosexuals who accepted church teaching and faithfully embraced celibacy, Mr. Sullivan said that Christ taught many difficult things.
"The church is simply conveying Christ's teaching to the modern world. In many cases it's difficult for us to understand. ... But church teaching has always been opposed to the standards of the world."
Francis DeBernardo, executive director of New Ways Ministry, an organization for gay Catholics that is not approved by the church, said that the document "has a very narrow understanding of homosexuality" that equates it with a "maniacal desire to have sex."
"Someone can be very deeply homosexual and still remain celibate," said Mr. DeBernardo, whose organization is based in Mount Ranier, Md.
He expects a mixed response from gay seminarians and priests, with some choosing to reveal their orientation, others to leave the seminary or priesthood, and others to "stay and fight." But the document will send a message of rejection to all gay Catholics and those who love them, he said.
The Rev. Thomas Reese, visiting scholar at Santa Clara University in Santa Clara, Calif., and the author of several books on the Catholic Church, said there may be problems interpreting the document because its language is different from the language of professionals who study human sexuality.
He believes its intent is to stop the ordination of any seminarian who has ongoing homosexual inclinations, even if that person is living a completely chaste life. But because there is no definition of "deep-seated homosexual tendencies," some bishops, seminary rectors and religious superiors may find some wiggle room, he said.
Father Reese said that arguments based on the sexual abuse scandal do not stand up to scrutiny.
"When you talk to the people who treated these abusive priests, you find that a lot of the ones who abused boys were in fact heterosexual" but targeted boys because they seldom spent time with girls or women, he said.
No one knows how many gay men are in the priesthood, although most estimates indicate the percentage is significantly higher than in the general population. The document will hurt such men who have served faithfully, Father Reese said.
"The Vatican is basically saying, 'We made a mistake in ordaining you.' That is going to be devastating morale-wise," he said.