Whose View of Life? Embryos, Cloning, and Stem Cells
http://www.100md.com
《新英格兰医药杂志》
The debate in America over abortion and research with human embryos is so polarized that it is easy to forget that today's passionately held views of the intrinsic moral status of the embryo are but the latest in an ever-evolving understanding of human biology and its implications for theology and philosophy. Jane Maienschein's delightful book Whose View of Life? is a welcome reminder — and, for optimists, represents the hope — that today's intransigence might someday yield to a humbler stance by all partisans in this debate. As she writes, "Seeing current debates in light of the past . . . can defuse the efficacy of the argument — even if not the passion of the arguer."
Maienschein begins with an illuminating walk through history, starting, as do so many learned discussions, with Aristotle, who advocated an epigenetic, gradualist view of life's origins. According to this theory, male and female contributions to the physical body produce an entity that is, at first, mere potential, until a life-generating force causes the potential to yield actual life. Such a view was held by early Catholic theologians, including Saint Augustine and Saint Thomas Aquinas, as well as Jewish and Islamic thinkers. A response to the epigenetic view came with the doctrine of materialist preformationism, a conviction that all the necessary elements of the final organism are present from the outset.
Maienschein writes:
At its heart, the debate was about whose view of life would prevail concerning when an individual life really can be defined as beginning. For epigenesists, [t]here is no chicken there in the egg, but only the background conditions that will make it possible for a chicken to come into being if a number of other conditions are also satisfied. . . . Yes, this occurs at some point rather than another. But deciding which point is a matter of definition and convention — it is not a matter to be dictated by some deep truth lying within. . . . In contrast, [for] preformationists or predeterminists who hold that the life and its form are laid down in the beginning or with fertilization . . . it is easiest to assert that each [embryo] is . . . fully alive and already an individual life. . . . If the coming together of material and inherited cells and nuclei is decisive, then apparently genes make the man.
She then continues with a historical walk through the laboratories of scientists who worked to understand the stages of embryonic development. These scientists slowly came to refute, at least at the physical level, some of the beliefs of the preformationists as they carefully demonstrated the absence of any preformed version of the final being who results. Later, however, the work of Gregor Mendel began to revive predeterminist views as attention turned to the role of genetics in the unfurling of embryonic development.
The book links these early explorations with today's heated debates in a way that is refreshing and helpful. Later chapters, which focus on the debate concerning embryonic research, stem-cell research, and cloning, make periodic references to the echoes of old arguments about the importance of genetics alone to guide development and the degree to which current opposition to embryonic research and cloning is often grounded in a surprisingly strong form of genetic determinism.
Alas, these chapters also include some minor errors of law and fact concerning federal policy. For example, there is confusion between restrictions on the funding of research that uses human embryos and restrictions on the funding of cadaveric fetal-tissue research; events surrounding the 1993 National Institutes of Health (NIH) Human Embryo Panel are slightly misrepresented; and, more amusingly, Harold Varmus, director of the NIH, is confused with Harold Shapiro, chairman of the National Bioethics Advisory Commission, in a discussion about the famous twin who led a report on cloning.
But these are small matters in comparison with the value of linking old debates to new ones in an effort to demonstrate that views change, that moral assessments evolve as surely as does the embryo itself, and that science, as it opens the next window on embryology, may yield even more divergent views on nascent life. Perhaps this book demonstrates conclusively that knowledge leads to uncertainty, which, in the cloning, stem-cell, and abortion debates, might be a very good thing.
R. Alta Charo, J.D.
University of Wisconsin Law School
Madison, WI 53706
racharo@wisc.edu(By Jane Maienschein. 342 )
Maienschein begins with an illuminating walk through history, starting, as do so many learned discussions, with Aristotle, who advocated an epigenetic, gradualist view of life's origins. According to this theory, male and female contributions to the physical body produce an entity that is, at first, mere potential, until a life-generating force causes the potential to yield actual life. Such a view was held by early Catholic theologians, including Saint Augustine and Saint Thomas Aquinas, as well as Jewish and Islamic thinkers. A response to the epigenetic view came with the doctrine of materialist preformationism, a conviction that all the necessary elements of the final organism are present from the outset.
Maienschein writes:
At its heart, the debate was about whose view of life would prevail concerning when an individual life really can be defined as beginning. For epigenesists, [t]here is no chicken there in the egg, but only the background conditions that will make it possible for a chicken to come into being if a number of other conditions are also satisfied. . . . Yes, this occurs at some point rather than another. But deciding which point is a matter of definition and convention — it is not a matter to be dictated by some deep truth lying within. . . . In contrast, [for] preformationists or predeterminists who hold that the life and its form are laid down in the beginning or with fertilization . . . it is easiest to assert that each [embryo] is . . . fully alive and already an individual life. . . . If the coming together of material and inherited cells and nuclei is decisive, then apparently genes make the man.
She then continues with a historical walk through the laboratories of scientists who worked to understand the stages of embryonic development. These scientists slowly came to refute, at least at the physical level, some of the beliefs of the preformationists as they carefully demonstrated the absence of any preformed version of the final being who results. Later, however, the work of Gregor Mendel began to revive predeterminist views as attention turned to the role of genetics in the unfurling of embryonic development.
The book links these early explorations with today's heated debates in a way that is refreshing and helpful. Later chapters, which focus on the debate concerning embryonic research, stem-cell research, and cloning, make periodic references to the echoes of old arguments about the importance of genetics alone to guide development and the degree to which current opposition to embryonic research and cloning is often grounded in a surprisingly strong form of genetic determinism.
Alas, these chapters also include some minor errors of law and fact concerning federal policy. For example, there is confusion between restrictions on the funding of research that uses human embryos and restrictions on the funding of cadaveric fetal-tissue research; events surrounding the 1993 National Institutes of Health (NIH) Human Embryo Panel are slightly misrepresented; and, more amusingly, Harold Varmus, director of the NIH, is confused with Harold Shapiro, chairman of the National Bioethics Advisory Commission, in a discussion about the famous twin who led a report on cloning.
But these are small matters in comparison with the value of linking old debates to new ones in an effort to demonstrate that views change, that moral assessments evolve as surely as does the embryo itself, and that science, as it opens the next window on embryology, may yield even more divergent views on nascent life. Perhaps this book demonstrates conclusively that knowledge leads to uncertainty, which, in the cloning, stem-cell, and abortion debates, might be a very good thing.
R. Alta Charo, J.D.
University of Wisconsin Law School
Madison, WI 53706
racharo@wisc.edu(By Jane Maienschein. 342 )