Why is the Catholic Church down on stem cell research?

[Ulteriority]

"so the problem is the way they are being obtained. Since in vitro is already opposed by the Church, permitting the usage of [in their mind] illicitly obtained embryos for scientific purposes can only deepen the error and compound the moral reprehensibility."

Incorrect. The problem with embryonic stem-cell research is NOT how the embryos were created, but merely the fact that they are being destroyed.

The fact that they were "already going to be discarded" is irrelevant. When the stem-cells are harvested, the embryos are STILL ALIVE, and the very act of harvesting kills them. Storm's logic about "will be destroyed either way" is like saying, "Cancer patients are already dying, so we might as well tear out their beating hearts for transplant." Just because they're going to be destroyed either way (though that's not necessarily true; some people do adopt children AS embryos, and even if not, they can survive in suspended animation indefinitely, the limbo many in fact face) doesn't mean we can ethically be the ones doing the destroying.

Far from it being about embryos being seen as morally "tainted" because they are from IVF, the teaching actually upholds the humanity of those conceived this way. Even if the Church approved of IVF, it would still certainly be against destroying the most vulnerable of human lives. The problem is emphatically NOT "how they were obtained" or came into existence in the first place, but simply the fact that they are being killed. Like abortion (of which embryo-destruction is essentially a form), the Church is baffled that anyone would see this as an issue of "sexual morality." From the Church's point of view, once a human life is in existence, the sex question is in the past at that point, and it becomes a Life issue, not a sex issue. This is about "Thou shalt not kill" and the irreducible value of each individual as not just a means to various ends.

There may be some additional concerns about such research creating a "moral hazard" in the form of creating demand for additional IVF embryos to use in further research, but this is not at all the main concern. The main concern is that human lives are being destroyed, that the littlest babies are being KILLED, not the question of where they come from.

Yes, the Church is also opposed to IVF, because it is against human dignity to be "engineered," to come into existence in a petri dish with no one else around but a clinician in a face-mask with a cup of your father's jerk-off jizz and eggs extracted from your mother in an incredibly invasive harvesting procedure, and then "implanted" by some third party like something out of an alien abduction (with your siblings left frozen in an indefinite limbo of liquid nitrogen in some lab somewhere)...rather than overflowing from the very act of marital love between your parents. (Which is why the Church approves of fertility treatments that enable natural conception within the conjugal act).

But, that doesn't invalidate the children so conceived, anymore than rape or extra-marital sex invalidates the children conceived in those ways. In fact, the children are the victims here, it's their dignity (or very lives) being violated, and the Church recognizes their full humanity nonetheless, which is why they can't be destroyed.

Now, when it comes to lines of stem cells ALREADY in existence (ie, the killing is in the past), scientists might be able to use these for research depending on how remote they are from the original act of murder. They do have to be careful about implicating themselves or encouraging the system to further itself. But assuming moral distance from the original act, these remaining lines might legitimately be used.