But it's also important to note that while there are many ways in which ASCs and ESCs overlap, in both research and therapies, they don't entirely overlap. From a basic science standpoint, ESCs are interesting in very different ways from ASCs, and in some cases their therapeutic uses might be different.

To me, comparison of ASCs to ESCs in this debate is a red herring and being misused by both sides. If one is opposed to ESCs for the moral reason of finding it unjustifiable to destroy an embryo it shouldn't matter if that ESC ends up only curing oily skin or curing every disease known to man. If it is immoral, it is immoral no matter what its uses are.

ESCs have potential to cure some diseases but the research is really in its infancy and it is unclear what knowledge will be gained and if any of that knowledge will be transferable to therapies. People like Fumento are correct to point out that ASC research has proved useful for treatments (although he uses the word "cures" which isn't entirely accurate and overstating *his* case) but to say that because they are successful we therefore do not need to work on ESCs is a false syllogism.

If a scientist could prove beyond a reasonable doubt that ESCs can cure one major disease and that ASCs will never cure that particular disease, would that be useful enough to destroy embryos? What about two? Or four? Or a dozen? When does the research become useful enough to destroy embryos?

ESC research is useful for science in ways that go beyond the scope of the public's understanding of the relationship of research to therapeutics. In the same way that ESC proponents appeal to the emotions of public to garner support, ESC opponents pull the false syllogism of ASC research to manipulate the utilitarian leanings of that public to convince them that they don't *need* ESCs. Implicit in that strategy, however, is that if it could be proven that we do need ESCs, then the moral argument against it won't hold up to public debate. That argument can and should hold up in the absence of ASCs. Which is why we should avoid comparisons between ESCs and ASCs and instead focus on acceptable, moral ways to get access to ESCs that don't involve destroying embryos.

Just going out on a limb here, but if you get stem cells without destroying embryos, then they are no longer Embryonic Stem Cells. In order to get ESCs, you need embryonic activity, don't you?

Well, that's part of the problem. Because this work is in its infancy, no one really has a good definition. One of the major differences of ASCs and ESCs is that ESCs are just really young ASCs. The sort of accepted definition is that an ESC is a cell that is totipotent (or near totipotent) meaning it can differentiate into any cell type. Embryos slough off cells all of the time, which is why you see reports recently of women having whole patches of regrown tissue in their body that are genetically their children's, or why you can get ESCs from umbilical cord blood.

See also, Justin's posts about the proposals of getting around destroying embryos below.

Embryonic stem cell advocates tend to understate or ignore the value of ASCs. Embryonic stem cell opponents tend to ignore the value of embryonic stem cells. Hostility to embryonic stem cells can bleed over to adult stem cells. I recently heard Charles Krauthammer argue that there was no evidence that stem cells could help paralysis victims.

So when you see a story like this one:

http://sg.news.yahoo.com/041128/1/3ovex.html

it serves as a reality check to both sides. Adult stem cells obviously have therapeutic value, AND stem cell research (including embryonic stem cell research) has great promise.

Adult stem cells are partially specialized. A tree analogy is apt: embryonic stem cells are the trunk of the tree and are capable of becoming any part of the tree. Adult stem cells are a branch of the tree. ASCs are capable of becoming any twig or leaf on that branch, but it can't become part of another branch.

The other advantage of embryonic stem cells are their youth.

It would be preferable if all the potential of embryonic stem cells could be had with adult stem cells. From a pure economic standpoint, they are easier to get. You would simply find and isolate the ASC you need from the patient's own body, and grow and use as needed.

You would also dodge a huge ethical minefield. And researchers don't get up in the morning wondering what moral boundary they should cross today. They would prefer to avoid the hassle.

While amorality is no excuse for immorality (if the research really were immoral), it seems curious that ESC opponents loudly argue against ESC research stating that these cells hold little promise. Why would the best experts in the field be so eager to waste their careers on a dead end?

Obviously the best experts have reason to believe that ESCs have special potential. It would be more honest for ESC research opponents to say "we oppose ESC research on moral grounds regardless of their potential."

Stephen Gordon said:
It would be more honest for ESC research opponents to say "we oppose ESC research on moral grounds regardless of their potential."

Gee Stephen, I thought that's what I have been saying. I could counter your question with this... Why would the best experts in the field be so eager to waste their souls on a risky prospect? It hasn't been conclusively proven that it is not a dead end, either.

Michael asked:
"When does the research become useful enough to destroy embryos??

My response to this is NEVER. Since teratoma are not embryos, any stem cells garnered from that source should at least be classified differently, perhaps as Teratoma Stem Cells, eh? I am still against the deliberate manipulation to create teratoma, though. Wouldn't it be ironic if teratoma couldn't provide stem cells that are as flexible as the embryonic stem cells are suppose to be.

I think there's a bit of the "100,000-word column" argument going on here. I've never gotten the sense from an opponent of ESC research that they were making a purely utilitarian argument. The question is: how long does every piece on the subject have to be?

However comparably (or not) you're willing to treat the technologies, it is clearly relevant to the ESC debate that ASCs have a bit of a good track record. That, I'd wager, is why the mainstream media tends to edit ASCs out of existence. In turn, it is the media silence on ASCs that justifies columns devoted entirely to them.

Smmtheory:

I was speaking generally, please don't assume I was refering to you. Yours is an honest position that I just happen to disagree with.

As Justin pointed out with his post, there has been dishonesty about ASC's on my side of the issue as well.

Justin:

Was my 322 word comment above too long? :-) Or was I making Smmtheory's mistake of thinking a general comment refered to me?

Merry Christmas guys. Thank you for a stimulating discussion over the last couple of weeks.

Stephen,

Sorry not to clarify: by the "100,000-word column" argument, I meant to indicate the complaint that a particular column doesn't address the entirety of an issue. In other words, the complaint is that the column is not 100,000 words long and therefore is not comprehensive.

Merry Christmas!