Thank you for your very reasonable last post. Your point is well taken that we must separate the intellectual and political aspects of our debate. On the political side of the issue, it seems we are in agreement. We both believe it is important to make sure that biomedical researchers are allowed to perform legitimate experiments on embryonic cells, because the potential benefits to humankind in terms of increased health and longevity are enormous. I, like you, also worry that ideologues could use the intellectual arguments that I have made in past posts (as well as my other writings) as a tool against the political outcome that we would both like to see.
As you say, only a minority of Americans believe that a single-cell embryo is equivalent to a human being (although I wouldn't refer to the 20 percent to 25 percent who seem to hold this view as a "small" minority). At the other end of the spectrum, it does seem likely that only a small minority hold my point of view with the one-cell embryo being metaphysically equivalent to other living human cells (although I would like to hear what Slate readers have to say about this). And, finally, I agree with you that a majority of Americans take an intermediate point of view, giving the one-cell embryo more respect than a skin cell, for example.
Clearly we are not in agreement on the intellectual side of the issue. But rather than continue this debate (readers can certainly get the gist of it from our previous posts), I think it is more useful to ponder the personal conflict between adherence to intellectual honesty and the need to compromise that honesty for the purpose of achieving certain political goals.
Tom, the easy way out is to write and speak only those ideas that support one's political goals, or to not say anything at all. Harold Shapiro told me that representatives of the fertility industry refused to testify before the NBAC on the question of human cloning. And I know several scientists and doctors who have publicly denounced human reproductive cloning, even though their personal points of view are quite different. Finally, many of my colleagues were angry with me for letting it be known (in my book) that the term "pre-embryo" was invented solely for the purpose of achieving pro-choice political goals (which I happen to support).
In the 1930s, the great philosopher Bertrand Russell was not afraid to challenge religious dogma in his outstanding book Religion and Science, which is still available after all these years. Today, it seems, some bioethicists (and I don't mean this personally) are much more interested in responding to the majority point of view and achieving consensus. Although I appreciate the rationale for taking this tack in the highly politicized world in which we currently live, I am saddened by the possibility that honest intellectual debate suffers as a consequence.
Finally, Tom, just because I am a scientist doesn't mean I can't wonder about metaphysics and human souls.
P.S. For the record: While it is perfectly reasonable to argue over philosophy and politics, it is important to get the scientific facts straight. Embryonic stem cells will grow into a disorganized mass of cells, not into a baby, if cultured in a petri dish. But, in fact, the same thing will happen if you grow an early human embryo in a petri dish. It is only when an embryo is placed back into a uterus, under the right conditions, that it has a chance of growing into a baby. Now, here's the information that the NBAC overlooked: Under the right conditions, mouse ES cells can be placed into a mouse uterus and grown into perfectly normal baby mice. The procedure was developed by Janet Rossant at Mount Sinai Hospital in Toronto. It was published in the Proceedings of the National Academy of Sciences (U.S.), Volume 90, Pages 8424-8428 (1993). The title of the article is "Derivation of completely cell culture-derived mice from early-passage embryonic stem cells." Most embryologists would agree that this is evidence of the likelihood that human ES cells could also be turned into babies, but (like human embryos) only under the right conditions and only within a woman's uterus.