(RNS) 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 scholars, 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?
Missouri lawmakers have declared their answer. By withholding both his signature and his veto, Democratic Gov. Jay Nixon signaled that he agreed and recently allowed the legislative answer to become state law.
''The life of each human being begins at conception," according to Senate Bill 793, which adds 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."
The bill makes Missouri the second state to adopt such language after a similar provision became law in South Dakota in 2005, and then survived a legal challenge in federal court in 2008.
Abortion providers will be required to include the language from the bill "prominently" on brochures that will be required for 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.
State Sen. Jim Lembke, a Republican and one of the bill's sponsors, 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. Scientists agree that when a sperm and egg unite, a living organism results.
But for philosophers and theologians, things get more complicated with the second sentence about abortion ending 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."
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.
The 40-day notion prevailed in the Roman 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. Pope John Paul II said "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, although more conservative evangelical churches largely embrace the Vatican's absolutist views.
But other faith traditions disagree, and have 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 different streams within 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 "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, a retired professor at the University of Hawaii and author of "Hindu Bioethics for the Twenty-First Century."
Critics, including Kate Lovelady of the Ethical Society of St. Louis, say the new law imposes one narrow religious view on others. "A lot of our members don't believe life begins at conception — that it's much more complicated than that."
As polarizing as the abortion debate is, all sides agree on the subject of religious doctrine incorporated into government health warnings.
''We shouldn't be crafting legislation based on differing faith systems," said Lembke, the bill's co-sponsor. "I'd much rather use our Constitution."
(Tim Townsend writes for the St. Louis Post-Dispatch in St. Louis, Mo.)
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