As I understand it, the religious objection to the use of stem cells is that potentially any one of them can become a human foetus. But what Yamanaka has demonstrated is that ANY cell in a human body can become a pluripotent embryonic stem cell, and hence eventually a human foetus. So the same religious arguments that apply to stem cells must also be applied to pluripotent cells, and hence to any cell in the body. Clearly God doesn't want us to do any biology at all.

Or would any religious apologist like to try and explain why the 'human potential' of a stem cell is different in principle from the 'human potential' of a pluripotent cell? Where precisely does God say that late twentieth-century technology is bad but early twenty-first technology is good?

Jon J, I understand it totally differently.

My understanding is that the religious objection is based on the view that an embryo (as opposed to a stem cell) is capable of becoming a human being (or is, in fact, a human being) and that the destruction of embryos for research is therefore unethical. It is the use of embryos, rather than stem cells, that give rise to the objection.

The new technique appears to sort that particular problem out quite nicely.

But this just pushes the question further back. An embryo initially consists of just one cell which has the potential to become human. Religious objectors to cloning have consistently refused to assign a particular point -- two cells, a hundred cells, a thousand cells? -- at which the embryo 'obtains' a soul, so we must assume that they believe a soul is possessed by an embryo from the first instant of its existence, not because of what it actually is but in what it has the potential to become. But if a skin cell can become a stem cell, and a stem cell can become an embryo cell, then these all obviously have the same potential and must therefore also have a soul. Reductio ad absurdum for the religious argument.

I find this article to be over emotive and unrealistic. One of the key problems with the approach of the article, and indeed much of the stem cell debate, is the premise that future (say 10 yrs +) therapeutic applications would be based solely on the scientific discovery of embryonic stem cells. The author details the advantages of not using embryonic stem cells as if they are new concepts, but they have been discussed by researchers from the beginning. Science was always going to cut out the unneeded and costly steps along with the ethical baggage once they had worked out the process of development. But even more importantly, 100% self pluripotent stem cells was always the key goal which is simply not obtainable with embryonic stem cells. The big political problem facing researchers is the lack of appreciation for the difference between the basic research process based predominantly on embryonic stem cells and the development of therapeutic tools mostly based on induced pluripotent stem cells. More embryonic research will be needed to compliment and validate that done with the genetically modified induced pluripotent stem cells.