One of the reflex principles of ethics states that, when there is a question about the morality of an act, the morally safer course must be followed. With respect to abortion, stem cell research, and any issue dealing with pre-born humans, the morally safer course must be followed. Once cells begin dividing, absent a miscarriage before birth, the only result is a living, breathing human baby. The morally safer course is to ensure the baby safely comes to term. Of course, pro-aborts would have us believe there is no doubt that the embryo is not human life.
In his support for stem-cell research, Orrin "Don't count your Hatches before they chicken" Hatch states that after discussing the matter with all manner of experts: religious, ethicists, and scientists, he can't believe that a mass of cells in a petri dish is human life. That is absurd. Medicial technology allows a fertilized embryo to be placed inside a woman so the baby can come to term. When does it become human life? When placed inside the mother? When it is born?
Fr. Stanley Jaki wrote a fascinating essay on the Galileo controversy called "Galileo Lessons". In the last section he addresses modern technological advances and the question of abortion vis-a-vis the Church. He brilliantly connects Galileo's statement upon signing his confession to the question of the continuance of the human embryo. "And yet it moves."
The Jaki book is worth getting just for those last few pages.
Not to be a killjoy, Sal, but Galileo never said "And yet it moves"; that's a myth that got tacked onto the Galileo legend by anti-Catholics.
Still, the metaphor is appropriate.