Like many topics in science today, the Stem Cell debate is stymied by two large gaps in the ability of either side to communicate. These two gaps are 'lack of information or knowledge', and 'lack of appropriate definition'.
The former, lack of information, is most readily seen when looking at any debate upon the ethics of Stem Cells, where in the very title a critical omission has been made.
There are two basic categories of stem cells that are proposed for therapeutic use today, and only one of them is considered in any way morally objectionable:
-Embryonic stem cells, which are derived from human embryos, and
-Adult stem cells, which are obtained from adult humans (either the patient or another)
Why, when there is an alternative, would people choose Embryonic stem cells? Well, the difficulty with Adult stem cells is their lack of flexibility. Although some types of adult stem cell can differentiate into (and thus supposedly heal) many different tissue types, none are thought to be as flexible as embryonic stem cells.
This is where the second gap in communications arises. Few people are willing to use a form of medication where someone is killed to save another, outside of urban myths regarding kidney theft. Therefore when someone proposes the use of cells derived from a killed embryo, there is a moral issue that needs resolution. The second gap I define regards the inability for the debating groups to decide upon a baseline fact, in this case: "What is life?"
To me at least, I know life to be the self-perpetuating process where things are created/born, consume, grow, interact with their environment and eventually die. A loose definition, but one which doesn't require a great deal of common sense to interpret. It seems obvious to me that when something is created that has the potential to fulfill the criteria of a living being, it is a living being. The fact that it hasn't been given the chance to fulfill all the criteria yet is irrelevant; it just needs time. An embryo is a baby in the making, and refuting that fact is simply wrong, on an academic and moral level.
When it is accepted that an embryo is a human on some level, it may then surprise some to note that the proponents of embryonic stem cell research propose that, despite being human, the embryo lacks some critical yet conspicuously undefined 'thing' which would make it a person. They propose that it is different to kill an embryo at the 8-cell stage than to kill one at the 16, and different to kill it at the 16-cell stage than at the blastocyst, and so on.
When dealing with a science which deals with human life, such as medicine or genetics, we have to maintain perspective and play it safe. When testing a new drug, every measure is taken to ensure that human life is not in jeopardy. Why, then, is human life 'risked' when the researchers in question cannot be certain that there is life at all?
When it is possible that human life is in jeopardy, every measure must be taken to remove this element, and that is simply not possible with conventional embryonic stem cell research.
However, all is not lost for those who desire the hypothetical health benefits of embryonic stem cells. Two primary means of acquiring stem cells without the killing of an embryo are becoming increasingly popular, and carry fewer moral issues to contend with.
Firstly is the storage of the placenta and cord of a newborn child; services already exist to store the organ (which contains enough embryonic stem cells to work with, it is thought), although these are quite expensive. Given that the placenta is generally discarded, there's really no issue here; if the expense can be afforded, placental cells can fulfill the role adequately, although this requires that a child be brought to term which is not always possible or desirable.
Secondly (and also requiring a child be brought to term), a routine procedure during IVF removes one of the cells of an 8-cell stage embryo for testing. This does not seem to cause the embryo any harm, and the cell is of precisely the type desired for stem cell research. This method/procedure carries with it the same moral issues as conventional IVF, but does not necessitate the deliberate killing of an embryo to achieve.
There is one other method proposed for the harvesting of embryonic cells, which is based on a fallacious argument. This method (which has several permutations) involves the creation of a 'doomed' embryo, where there is no chance the embryo could grow to a newborn child due to some inbuilt/engineered/inflicted defect. Therefore, it is declared, the stem cells obtained carry no moral issue. This argument makes no sense in perspective; there is no functional or moral difference between engineering the ultimate death of an embryo and doing it directly by disassembly and harvesting.
Although there are methods of achieving embryonic stem cells without great moral objection, the final question needs be raised; why bother? As things stand, although embryonic stem cells seem to carry the most potential, the technology to put them to use is in its infancy and cannot be guaranteed to come to maturity anytime soon. Meanwhile, adult stem cells have shown more success than embryonic cells despite their lesser flexibility, and because they can be obtained from the patient directly there is normally no problem with compatibility (a potential concern with embryonic cells, which could be destroyed by the body after treatment anyway due to being taken from someone else).
In conclusion, it is the opinion of this writer that the morality of harvesting embryonic stem cells through conventional means is objectionable and based upon an idealistic blindness to the realities of the situation. Embryonic stem cells can be obtained without killing an embryo, with some difficulty, but adult stem cells are easier to obtain and have shown more actual success so far.