It's a question that has perplexed philosophers, theologians and scientists for thousands of years.

Pythagorean Greeks, early Christian church fathers, Talmudic rabbis, Sunni and Shia thinkers, Hindu brahmin and modern bioethicists have grappled with the fundamental, ultimately unknowable, mystery: At what point in our biological development are we infused with a soul? At what point do we become human?

On May 14, the final day of their legislative session, Missouri lawmakers declared the answer, and last month, by withholding his veto, Gov. Jay Nixon signaled that he agreed. On Aug. 28, their answer will become the law of the land.

"The life of each human being begins at conception," according to Senate Bill 793, which will add new regulations to the state's 24-hour informed consent law for abortions. "Abortion will terminate the life of a separate, unique, living human being."

Those words will be displayed "prominently" on brochures that abortion providers will be required to hand out to every woman seeking the procedure — even if they don't happen to believe the Christian theology the words represent.

"Those are not sentiments that all the world's religions, or all the people in the state, believe in," said Paula Gianino, president and CEO of Planned Parenthood of the St. Louis Region and Southwest Missouri.

But supporters of the new law say they see no conflict between religion and the law's definition of life.

Sen. Jim Lembke, R-Lemay, one of the sponsors of the bills, said the language on the new brochures "is not a religious statement. It's a scientific statement."

Those with differing beliefs "will have to take all the information given to them and make an informed decision," Lembke said.

The sentiment expressed in the first of the new brochures' two sentences — that life begins at conception — has been part of Missouri law for nearly a quarter century. And scientists agree that when a sperm and egg unite, a living organism results.

But for philosophers and theologians, things get more complicated with the new law's second sentence, which asserts that abortion ends the life of a 'separate, unique, living human being."

"The distinction is between human life where you're talking about an organism as opposed to a human life in a moral sense," said Bonnie Steinbock, professor of philosophy at the State University of New York at Albany. "Those are two different debates that go back to Aquinas and the issue of ensoulment."

SOULED VS. UNENSOULED

Aquinas, and Augustine before him, wrestled with concepts first introduced by Aristotle in the fourth century B.C. Aristotle believed that a soul could only inhabit a fetus when that fetus began to look human, a timetable he set at 40 days for men and 90 days for women.

While some early Christian theologians condemned abortion at any stage, the notion of 40 days prevailed in the Catholic church until the 19th century, when Pope Pius IX removed the distinction between souled and unensouled fetuses from church doctrine.

Since then, the Catholic church has conceded that man can never know empirically when an embryo gains its soul.

But Pope John Paul II wrote that the point is more or less moot when it comes to abortion, saying that "the mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo."

Protestant denominations have a variety of positions on life's beginnings. In recent decades, more conservative evangelical churches have shared the Vatican view, giving Catholic leaders political partners.

But other faith traditions disagree, and have been doing so for centuries.

"The Talmud says that from the moment of fertilization until 40 days, the embryo has a status of being nearly liquid," said Rabbi Yehiel Poupko, Judaic scholar at the Jewish Federation of Metropolitan Chicago."The question for Jewish law is not when does life begin, but when is the embryo entitled to the justice and compassion of society?"

Islamic law closely follows Jewish law, though followers of different steams of Islam have various views, said Abdulaziz Sachedina, a professor of Islamic studies at the University of Virginia and author of "Islamic Biomedical Ethics."

Most Sunni Muslims, members of the largest stream of Islam, "believe that life begins at the turn of the first trimester," Sachedina said.

Hindus believe in reincarnation, so life beginning "at conception" creates theological problems.

"Life cannot begin at conception when our lives have not ended in the first place," said Cromwell Crawford, emeritus professor of world religions at the University of Hawaii and author of "Hindu Bioethics for the Twenty-First Century."

'A RELIGIOUS OPINION'

Critics say the new law imposes one narrow religious view on others.

Kate Lovelady, leader of the Ethical Society of St. Louis said "a lot of our members don't believe life begins at conception — that it's much more complicated than that."

According to the Guttmacher Institute, a nonprofit organization that supports abortion rights, 28 percent of women obtaining abortions in 2008 said they had no religious affiliation, the same percentage of Catholic women, and up from 22 percent in 2000. Protestants made up 37 percent of abortions in 2008. Those women who responded "other" represented 7 percent.

Sen. Tom Dempsey, R-St. Charles, one of the bill's co-sponsors, said he heard no religious objections to the legislation.

"During the discussion of the bill, the filing of bill, the process of bill, at no time did I receive any objections to that language, nor hear from any constituents about the language from people of any faith," he said.

In July, Gov. Jay Nixon, a Democrat, avoided signing or vetoing the bill by citing a constitutional rule that automatically creates law from a bill that goes unsigned by the governor. Nixon declined a request to comment for this article.

Missouri became the second state to adopt the language after a similar provision became law in South Dakota in 2005, then survived a legal challenge in federal court in 2008.

Kathi DiNicola of Planned Parenthood Minnesota, North Dakota, South Dakota, said the organization has complied with the federal court decision. But, she said, "we have not seen women change their minds as a result of our doctors having to deliver this language."

As polarizing as the abortion debate is, on the subject of religious doctrine incorporated into government health warnings, all sides agree.

"We shouldn't be crafting legislation based on differing faith systems," Lembke said. "I'd much rather use our Constitution."