William B. Hurlbut is a medical doctor and a consulting professor at Stanford University Medical Center’s Neuroscience Institute in California. A member of the President’s Council on Bioethics since 2002, Dr. Hurlbut has also worked on astrobiology projects with NASA. Vision contributor Dan Cloer recently asked him about one of his primary fields of interest: the continuing ethical concerns regarding embryonic stem-cell research.
DC How does stem-cell research fit within the greater picture of human biology?
WH It’s a very early science, but it clearly symbolizes the beginning of the era of developmental biology. We sequenced the human genome, and we are studying the proteins that the genes produce. From here on, biology is moving back into the realm of living things. We spent about a hundred years studying molecular biology, and we will continue. But now we are assembling the parts back into the living organism, understanding how the parts contribute to the living process.
DC Is this why you believe it’s a problem to use so-called leftover embryos from in vitro fertilization (IVF)—that each is an integrated system that is being disturbed to do this research?
WH Yes. This is a living human embryo. If we are going to study human embryogenesis, we are going to have to learn how to do it without creating and destroying human embryos, because once we start doing that, we will find an enormous number of possible ways to use the embryos. The idea that we are just going to use them to get embryonic stem cells is wrong. There are many uses for human embryos. So we have to break the problem into parts that are not themselves units of moral concern. We can study parts apart from the whole, and that’s what I have suggested, but we can’t study the full, integrated organism without breaching the fundamental moral concern of instrumental use of human life.
DC How will your proposal of “altered nuclear transfer” (ANT) allow the study of human development without using a human embryo?
WH The whole idea is to create only a subset of development but not the integrated potential that characterizes a human embryo. It uses the same technology as somatic cell nuclear transfer, with a preemptive alteration. Preemptive is the key: the altering of the genetics of the body cell or the cytoplasm of the egg before joining the two. The “starting ingredients” are altered in such a way that what is created does not become a living being but only a cellular process akin to a tissue culture.
That’s the key moral difference with the ANT approach. If you think of a living being as an integrated unit or complete system, ANT would break the system into subsets and study only a subsystem. Just as you can study, without moral concern, enzymatic systems in dishes or test tubes, you can also study some cellular development in test tubes, so long as it is not the integrated unit.
Altered nuclear transfer would allow you to probe and inquire into the factors necessary for the developmental process, while still not creating an embryo. It would teach us something about the trajectories involved in overall embryogenesis using partial and incomplete trajectories. In other words, if embryogenesis is A-B-C, you could study the interaction of A and B, and of B and C, and figure out how the whole integrates.
The point is that what you get is so different from the integrated whole, which constitutes a human embryo, that it is morally different. What’s created is not a deficiency in a being but an insufficiency in the ability to become a living being. So you never get that which is the subject of moral concern.
DC This seems a fantastic opportunity, but I do not hear a lot of enthusiasm for it.
WH There is a wide base of support for this. Some groups have objected that it sets the stage for intervention in human life. But I don’t think so. If they would examine it, they’d see that it’s just exactly the opposite.
“Some groups have objected that it sets the stage for intervention in human life. But I don’t think so. If they would examine it, they’d see that it’s just exactly the opposite.”
DC So ANT doesn’t become a window into preimplantation genetic alterations and make human genetic engineering and germ-line intervention more accessible?
WH No, exactly the opposite. It would preempt such explorations, because it would provide embryonic stem cells—or the equivalent, actually—in a form that is not a human embryo. It would therefore prevent the funding of unrestrained explorations with human embryos. The genetic alteration that would be essential for ANT would not set a precedent for germ-line transformation, simply because it is neither a germ-line nor an embryonic process. I think there is nothing to be gained by opposing ANT. It would provide us a tool for studying embryogenesis, in part; but otherwise that knowledge is going to come from studying natural human embryos. If anything, it affirms the inviolability of natural human life—that we must not arrogantly intervene in human development for purposes other than the clear benefit of the emerging individual life. ANT would establish the primacy of ethical principle and underscore the significance of a respectful attitude toward incipient human life.
The quickest way to get germ-line interventions in human development is to not have a project like ANT. When you allow the study and instrumental use of human embryos, saying that they have no moral standing, it is only a small step to playing around with the genetics to make a better human being. I think we need to step back and be respectful of that profound complexity that is a part of our natural endowment. I’m certainly in favor of healing. Medicine is a healing profession, not a blanket invitation to remake the human species.
DC How do politics, science and religion converge in addressing our sense of what the embryo is?
WH You can’t solve a problem like this with a purely political process, because all you end up with is the triumph of one perspective over another. The victory of partisan politics would not serve either our society or the future of our science. What we need is something that does not leave part of the population embittered: what we need is social consensus.
“If you don’t understand the biology, there’s not much point in talking about ethics. Much in bioethics is confused because of inaccurate understanding of the science.”
Science alone cannot answer the question of the moral standing of a living being, because it has a limited realm of inquiry. Its methodology is restricted to empirical studies. Science can tell what is happening at some level, but it can’t tell you why, or what it means morally. But if you don’t understand the biology, there’s not much point in talking about ethics. Much in bioethics is confused because of inaccurate understanding of the science. So unless you get the science right, you can’t even think about the moral issue. You won’t have any sense of what’s happening. You have to understand what the fundamental questions and problems are before you can address them. The science is essential to define what a living being is and what it becomes at its various stages. The moral philosophy and religious perspectives can then contribute thoughts about how to regard that unfolding life.
My perspective is that once you have a living human being, even in its earliest phases of development, you have the initiation of the organism that begins with fertilization and ends with natural death. And it’s that full spectrum of living existence that we should honor with our protection and moral principle.
DC The popular term, of course, is emergence—that life emerges from this clump of cells. That’s not a correct view of this process from your perspective?
WHI do like this word, because it raises us above pure reductionism. Reductionism tends to break a thing into its parts and then regard the parts as all there is. So then you come to think of human existence as mere chemistry. The fact that chemicals assembled in a certain way can express, or manifest, consciousness is an extraordinary and inexplicable reality. To that expression of the properties not apparent in the parts, we assign the term emergence. So I like the word; but the reason I assign moral worth to the human embryo is that those emergent properties are already harnessed in the potential of that unfolding life. It’s a potency, an engaged and effective potential in process. It’s not like the chemicals on a chemist’s shelf that could be mixed to form a reaction. This is a reaction already in process, a being with a drive in the direction of its fullness of form. As it unfolds, its various properties will be manifest: it will express the emergent properties already present in its initial formation.
“You know very well that if you had been used for an experiment as an embryo, even at the one-cell state, that would have broken the continuity that unfolded into your fully expressed being.”
You know very well that if you had been used for an experiment as an embryo, even at the one-cell state, that would have broken the continuity that unfolded into your fully expressed being. Clearly, when you destroy the single-celled embryo in a dish, you are interrupting the process which is on the trajectory to expressing what we recognize socially to be a human person.
DC You’ve told me previously that you have been traveling around the world with this message, but concern about research using human embryos from IVF clinics seems to be uniquely American. What sort of response are you receiving?
WH I’ve been in six continents in the last couple of years, and I think there is apprehension worldwide. Everywhere in the world there is a little bit of uneasiness about using human embryos, regardless of their source. And in many places in the world there is not just uneasiness but opposition to intentionally creating human embryos for instrumental use. There are societies that simply will not use leftover IVF embryos; some do not even allow their creation. Even where they do allow individual choice to produce and freeze embryos, there are some societies that won’t allow them to be thawed out and used instrumentally, believing that those embryos were created not for a scientific project of public endorsement but for private use.
The United States comes under such a heading with federal policy that allows individuals to create those embryos, but we do not allow any federal funding for anything that endangers or destroys a human embryo, regardless of its source.
A few countries explicitly do allow therapeutic cloning: Sweden, the United Kingdom, Israel, South Korea and several other Asian countries. But take a country like the United Kingdom: there is a very restricted set of uses for the embryo. So a caution is expressed. In the United Kingdom, in vitro fertilization—which was, of course, invented there—itself created a controversy as to whether society should fund it and how much could be done to improve it.
In 1984 the Warnock Commission issued a statement that limited research to the first 14 days. They used principles at that time which they thought were scientifically legitimate, but none of these so-called scientific justifications has held up to deeper scrutiny. There really was not a deep moral analysis. Even what moral analysis was done used a preset utilitarian approach and incomplete scientific information. That “14 days” number has become a superstition, a received tradition that has been handed on from society to society. It does not hold up to moral scrutiny. The United States has the most active dialogue to challenge it. But other countries are involved in this dialogue. In fact, a year ago the United Nations passed a nonbinding mandate calling for a moratorium on all forms of human cloning. This reflects worldwide disquiet about where the science is going and what’s involved in the creation and destruction of human lives.
DC You’ve called ANT a win-win proposition. How so?
WH You begin with the assumption that both sides in this difficult debate are defending important human “goods,” which I believe is a true assumption. Then the goal should be to try to preserve both of those goods: advances in medical science and preservation of fundamental, traditional moral principle. ANT will allow that; it’s the third option that recognizes the good of both sides and allows both to go forward.
DC There are different tracks of research—embryonic stems cells, adult stem cells—all aiming toward cell therapies. But through ANT you could also create windows into embryogenesis itself, which could lead to regenerative therapies.
WH We all want the positive medical benefits of stem-cell research, and I think many of them will come from the use of adult stem cells. We are beginning to understand how the organism is knit together. The study of embryonic stem cells is a crucial step in this, and we would want to study them if there were no moral issues. We will eventually learn how to do this: whether through altered nuclear transfer, reprogramming, or a range of other possible approaches, we’ll get equivalent cells. It’s just a matter of putting the effort into the project.
DC Do you believe your medical training gives you a different sense of life than other researchers?
WH My medical training gives me the sense that medical interventions are justified by the healing purposes—that medicine is a limited prerogative, not an open invitation to tinker with human biology. What we need to do is find ways to cure people. I think we have a wonderful future in medicine, but we need to set the moral frame for the future. And that’s what my project tries to do. If we don’t defend the whole, we are going to mess up with the parts. But if we start with the affirmation that the whole living human, across all of its stages of development, is the being that we’re trying to protect, then we will start with an appreciation for life and will use the rest of our tools in a much more positive way.
If, however, we decide that human organisms at any stage of their development are mere resources—utilities for projects serving other people—that logic of justification could open some tragic abuses. Maybe not in the United States, but somewhere in the world, someone will eventually create and harvest human embryos at later stages of development, because that is where you can get the more useful cells, tissue and organs. So we need, right now, to do the hard work of defining with clarity and precision the moral boundaries we are trying to protect, and then we need to get worldwide agreement. Otherwise we are going to have an outsourcing of ethics. People are just going to take their research projects and medical and clinical applications to countries that allow them and simply avoid or override moral principle. That would lead to tragic conflicts in the world.
On the other hand, if we follow positive principles, we could have worldwide collaboration and find ways to advance medical science profoundly. I’m excited about that prospect.