Historically, philosophers of biology have tended to sidestep the problem of development by focusing primarily on evolutionary biology and, more recently, on molecular biology and genetics. Quite often too, development has been misunderstood as simply, or even primarily, a matter of gene activation and regulation. Nowadays a growing number of philosophers of science are focusing their analyses on the complexities of development, and in Embryology, Epigenesis and Evolution Jason Scott Robert explores the nature of development against current trends in biological (...) theory and practice and looks at the interrelations between development and evolution, an area of resurgent biological interest. Clearly written, this book should be of interest to students and professionals in the philosophy of science and the philosophy of biology. (shrink)

What do biologists want? If, unlike their counterparts in physics, biologists are generally wary of a grand, overarching theory, at what kinds of explanation do biologists aim? A history of the diverse and changing nature of biological explanation in a particularly charged field, "Making Sense of Life" draws our attention to the temporal, disciplinary, and cultural components of what biologists mean, and what they understand, when they propose to explain life.

In lieu of an abstract, here is a brief excerpt of the content:Who or What is the Preembryo?S.J. Richard A. McCormick (bio)IntroductionAlthough widely used by scientists, the term "preembryo" has raised some suspicions. Histopathologist Michael Jarmulowicz (1990), for example, asserts that the term was adopted by the American Fertility Society (AFS) and the Voluntary Licensing Authority (VLA) in Britain "as an exercise of linguistic engineering to make human embryo research more palatable to the general public."I cannot speak for the VLA, (...) but I can clarify that this was not the motive of the AFS. As a member of the AFS ethics committee that discussed and adopted this terminology, I know that our discussion was not tied to embryo research or moral issues. The term "preembryo" was adopted because the earliest stages of mammalian development primarily involve establishment of the nonembryonic trophoblast, rather than the formation of the embryo. As Clifford Grobstein (1988, p. 61), a distinguished basic scientist who also sat on the AFS committee notes:The scientific rationale for the term preembryo... is its greater accuracy in characterizing the initial phase of mammalian and human development.... The status implications of such a change in terminology were not at issue in the discussion.This is not to say that the moral status of the preembryo is not a concern worthy of independent consideration. It is an important question with significant practical implications, especially in the context of in vitro fertilization. At stake are issues such as: (1) what may be done to preembryos before transfer; (2) whether all preembryos must be transferred; and (3) what may be done to preembryos that are not transferred (Ethics Committee of the American Fertility Society (AFS) 1986, p. 29S). Furthermore, emergency treatment of rape cases may also depend on such a determination. [End Page 1]Cryopreservation, which entails freezing unused preembryos for possible later use, is one example of a procedure that raises issues associated with the moral status of the preembryo. Cryopreservation decreases the number of stimulated egg recovery cycles a woman must undergo and increases flexibility in transfer protocols. But thawing of the preembryos is not a completely benign process; significant numbers of the preembryos die in the process and injury cannot be excluded.In addition, down the road a year or so lies preimplantation genetic diagnosis, now being tested in several centers of reproductive research. This would involve the removal of one or more cells from a preembryo developing in vitro. The DNA from these cells would be studied and then only genetically normal preembryos would be transferred. With the growth in knowledge about single gene defects and the rapid advance of amplification technology, which allows gene visualization, it is not difficult to imagine scientists embarking on a variety of micromanipulations of the preembryo for the sake of gaining knowledge.Not all research with gametes involves preembryos, but clearly some experiments and procedures await resolution of the moral status of the preembryo. I contend in this paper that the moral status—and specifically the controversial issue of personhood—is related to attainment of developmental individuality (being the source of one individual). This contrasts with the view that holds that personhood occurs earlier, at the point of genetic uniqueness. I believe that an embryo that has developed to the point where it can be one individual and one individual only, differs in moral status from a preembryo that has not, even if in many cases we may choose to treat them similarly.The Scientific UnderpinningsTwo things must be kept in mind—and in a sense, in tension—in turning to science for help in assessing the status of the preembryo. First, science is not competent to decide the question of personhood or ensoulment. As the Catholic document, Declaration on Procured Abortion, which I will return to later, notes: "It is a philosophical problem" (Congregation for the Doctrine of the Faith (CDF) 1974, p. 10, endnote 19). On the other hand, another Catholic document, Donum vitae(CDF 1987), notes that the conclusions of science provide a "valuable indication" for reason's deliberations about personhood. We might say that if science cannot decide the question of personhood, neither can it be decided without science.For my review of embryological science... (shrink)

In the face of the moral pluralism that results from the death of God and the abandonment of a God's eye perspective in secular philosophy, bioethics arose in a context that renders it essentially incapable of giving answers to substantive moral questions, such as concerning the permissibility of abortion, human embryonic stem cell research, euthanasia, etc. Indeed, it is only when bioethics understands its own limitations and those of secular moral philosophy in general can it better appreciate those tasks that (...) it can actually usefully perform in both the clinical and academic setting. It is the task of this paper to understand and reevaluate bioethics by understanding these limits. Academic bioethicists can analyze ideas, concepts, and claims necessary to understanding the moral questions raised in health care, assessing the arguments related to these issues, and provide an understanding of the different moral perspectives on bioethical issues. In the clinical setting, bioethicists can provide legal advice, serve as experts on IRBs, mediating disputes, facilitating decision-making and risk management, and clarifying normative issues. However, understanding this is only possible when one understands the history, genesis, and foundations of bioethics and its inability to provide a resolution to postmodern moral pluralism. (shrink)

In this essay, I attempt to provide answers to the following four queries concerning the metaphysics of early human embryogenesis. (1) Following its first cellular fission, is it coherent to claim that one and only one of two “blastomeric” twins of a human zygote is identical with that zygote? (2) Following the fusion of two human pre-embryos, is it coherent to claim that one and only one pre-fusion pre-embryo is identical with that postfusion pre-embryo? (3) Does a live human being (...) come into existence only when its brain comes into existence? (4) At implantation, does a pre-embryo become a mere part of its mother? I argue that either if things have quidditative properties or if criterialism is false, then queries (1) and (2) can be answered in the affirmative; that in light of recent developments in theories of human death and in light of a more “functional” theory of brains, query (3) can be answered in the negative; and that plausible mereological principles require a negative answer to query (4). (shrink)

When Did I Begin? investigates the theoretical, moral, and biological issues surrounding the debate over the beginning of human life. With the continuing controversy over the use of in vitro fertilization techniques and experimentation with human embryos, these issues have been forced into the arena of public debate. Following a detailed analysis of the history of the question, Reverend Ford argues that a human individual could not begin before definitive individuation occurs with the appearance of the primitive streak about two (...) weeks after fertilization. This, he argues, is when it becomes finally known whether one or more human individuals are to form from a single egg. Thus, he questions the idea that the fertilized egg itself could be regarded as the beginning of the development of the human individual. The author also differs sharply, however, from those who would delay the beginning of the human person until the brain is formed, or until birth or the onset of conscious states. (shrink)

The phenomenon of twinning in early fetal development has become a popular source for doubt regarding the ascription of moral status to early embryos. In this paper, the possible moral basis for such a line of reasoning is critically analysed with sceptical results. Three different versions of the argument from twinning are considered, all of which are found to rest on confusions between the actual division of embryos involed in twinning and the property of early embryos to be divisible, be (...) based on highly questionable ethical assumptions, or to imply inconsistent claims regarding the moral importance of potentiality and/or the moral status of embryos. This is taken to expose a number of related inconsistencies in the moral basis of pro-life positions. In particular, ascribing moral significance to the property of being (in)divisible is found to be incompatible with the claim that human individuals possess unique values which could underpin an absolute moral ban on murder. (shrink)

The main objection to human embryonic stem cell research is that it involves killing human embryos, which are essentially beings of the same sort that you and I are. This objection presupposes that we once existed as early embryos and that we had the same moral status then that we have now. This essay challenges both those presuppositions, but focuses primarily on the first. I argue first that these presuppositions are incompatible with widely accepted beliefs about both assisted conception and (...) monozygotic twinning. I then argue that we never existed as embryos. If this last claim is right, killing an embryo does not kill someone like you or me but merely prevents one of us from existing. (shrink)

When does a human being begin to exist? We argue that it is possible, through a combination of biological fact and philosophical analysis, to provide a definitive answer to this question. We lay down a set of conditions for being a human being, and we determine when, in the course of normal fetal development, these conditions are first satisfied. Issues dealt with along the way include: modes of substance-formation, twinning, the nature of the intra-uterine environment, and the nature of the (...) relation between fetus and mother (connection, parthood, dependence). (shrink)

The Standard View of personal identity says that someone who exists now can exist at another time only if there is continuity of her mental contents or capacities. But no person is psychologically continuous with a fetus, for a fetus, at least early in its career, has no mental features at all. So the Standard View entails that no person was ever a fetus--contrary to the popular assumption that an unthinking fetus is a potential person. It is also mysterious what (...) does ordinarily happen to a human fetus, if it does not come to be a person. Although an extremely complex variant of the Standard View may allow one to persist without psychological continuity before one becomes a person but not afterwards, a far simpler solution is to accept a radically non-psychological account of our identity. (shrink)

Review essay of The Philosophy of Experimental Biology by Marcel Weber (Cambridge University Press, 2005).

Provides links to Internet resources in the field of international relations. Includes resources on diplomacy, history, and politics; economics and international management; international law; international organizations; regional studies; research institutes; United States government resources; and more.

This book explores the scope and limits of the concept of personDS a vexed question in contemporary philosophy. The author begins by questioning the methodology of thought-experimentation, arguing that it engenders inconclusive and unconvincing results, and that truth is stranger than fiction. She then examines an assortment of real-life conditions, including infancy, insanity andx dementia, dissociated states, and split brains. The popular faith in continuity of consciousness, and the unity of the person is subjected to sustained criticism. The author concludes (...) with a look at different views of the person found in Homer, Aristotle, the post-Cartesians, and contemporary cognitive science. (shrink)

According to Peter van Inwagen, visible inanimate objects do not, strictly speaking, exist. In defending this controversial thesis, he offers fresh insights on such topics as personal identity, commonsense belief, existence over time, the phenomenon of vagueness, and the relation between metaphysics and ordinary language.

The usual way for new cells to come into being is by division of old cells. So the zygote, which is a—new—single cell formed from two, the sperm and ovum, is an exception. Textbooks of human genetics usually say that this new cell is beginning of a new human individual. What this indicates is that they suddenly forget about identical twins.

I consider the argument, thought to clinch the moral case for use of a human embryo solely as a means, that only a human individual can be a person, because it can happen at any time before formation of the primitive streak that an embryo splits into monozygotic twins, no embryo in which the primitive streak has not formed is a human individual, and therefore no embryo in which the primitive streak has not formed is a person. I explore the (...) following proffered arguments for : indivisibility is a necessary condition of individuality, nonidentity of an embryo with successor twins impugns the embryo’s individuality, and totipotency of an embryo’s constituents is inconsistent with the embryo’s being a human individual. These arguments are tested and found wanting; so too is an alternative to, the argument that indivisibility is intrinsic to personhood. Whereupon is unsustained. In search of ways to rehabilitate the nonindividuation argument, I canvass alternative metaphysical views and inquire further into biological individuality, but find that the argument cannot be saved. I conclude by analyzing where this leaves matters concerning the morality of embryo use. (shrink)

The Standard View of personal identity says that someone who exists now can exist at another time only if there is continuity of her mental contents or capacities. But no person is psychologically continuous with a fetus, for a fetus, at least early in its career. has no mental features at all. So the Standard View entails that no person was ever a fetus---contrary to the popular assumption that an unthinking fetus is a potential person. It is also mysterious what (...) does ordinarily happen to a human fetus, if it does not come to be a person. Although an extremely complex variant of the Standard View may allow one to persist without psychological continuity before one becomes a person but not afterwards, a far simpler solution is to accept a radically non-psychological account of our identity. (shrink)

What makes a biological entity an individual? Jack Wilson shows that past philosophers have failed to explicate the conditions an entity must satisfy to be a living individual. He explores the reason for this failure and explains why we should limit ourselves to examples involving real organisms rather than thought experiments. This book explores and resolves paradoxes that arise when one applies past notions of individuality to biological examples beyond the conventional range and presents an analysis of identity and persistence. (...) The book's main purpose is to bring together two lines of research, theoretical biology and metaphysics, which have dealt with the same subject in isolation from one another. Wilson explains an alternative theory about biological individuality which solves problems which cannot be addressed by either field alone. He presents a more fine-grained vocabulary of individuation based on diverse kinds of living things, allowing him to clarify previously muddled disputes about individuality in biology. (shrink)

Un replanteamiento de la cuestión del aborto desde la perspectiva de la teleología orgánica del materialismo filosófico.

A basic component of moral objections to embryonic stem cell research is the claim that human embryos have the same moral status as typical adult human beings. There is no reason to accept this claim, however, unless adult humans once existed as embryos—that is, unless the developmental history of adult humans contains embryos to which the adults are numerically identical. The purpose of this paper is to argue that there are no such identities, and hence that no adult human being (...) ever existed as an embryo. (shrink)

Michael Lockwood has recently concluded that it can be morally permissible to perform potentially damaging non-therapeutic experiments on live human (pre)embryos. The reasons he provides in support of this conclusion commit him inter alia to the following controversial theses: (i) an organism's potential for twinning bears critically on the identity conditions for that organism; and (ii) functionally intact mentality-mediating neurological structures play a critical role in establishing the identity conditions for human organisms. I argue that Lockwood has given us no (...) good reason to endorse either of these theses and, hence, that he has given us no good reason to believe that it can be morally permissible to perform potentially damaging non-therapeutic experiments on live human (pre)embryos. (shrink)

This paper argues that the consensus physicalist antireductionism in the philosophy of biology cannot accommodate the research strategy or indeed the recent findings of molecular developmental biology. After describing Wolperts programmatic claims on its behalf, and recent work by Gehring and others to identify the molecular determinants of development, the paper attempts to identify the relationship between evolutionary and developmental biology by reconciling two apparently conflicting accounts of bio-function – Wrights and Nagels (as elaborated by Cummins). Finally, the paper seeks (...) a way of defending the two central theses of physicalist antireductionism in the light of the research program of molecular developmental biology, by sharply reducing their metaphysical force. (shrink)

A. N. Prior; XIV—Time, Existence and Identity, Proceedings of the Aristotelian Society, Volume 66, Issue 1, 1 June 1966, Pages 183–192, https://doi.org/10.1093/.

-- 2. La Gnoseología como filosofía de la ciencia (parte I, sección 2) ; Historia de la teoría de la ciencia (parte I, sección 3) -- 3. El Sistema de las doctrinas gnoseológicas ; Las cuatro familias básicas (parte II, sección 1) -- 4. El sistema de las doctrinas gnoseológicas ; Descripcionismo (parte II, sección 2) ; Teoreticismo (parte II, sección 3) -- 5. Adecuacionismo (parte II, sección 4) ; Circularismo (parte II, sección 5) ; Glosario.

I consider the argument, thought to clinch the moral case for use of a human embryo solely as a means, that only a human individual can be a person, because it can happen at any time before formation of the primitive streak that an embryo splits into monozygotic twins, no embryo in which the primitive streak has not formed is a human individual, and therefore no embryo in which the primitive streak has not formed is a person. I explore the (...) following proffered arguments for : indivisibility is a necessary condition of individuality, nonidentity of an embryo with successor twins impugns the embryo’s individuality, and totipotency of an embryo’s constituents is inconsistent with the embryo’s being a human individual. These arguments are tested and found wanting; so too is an alternative to , the argument that indivisibility is intrinsic to personhood. Whereupon is unsustained. In search of ways to rehabilitate the nonindividuation argument, I canvass alternative metaphysical views and inquire further into biological individuality, but find that the argument cannot be saved. I conclude by analyzing where this leaves matters concerning the morality of embryo use. (shrink)

A higher order potential analysis of moral status clarifies the issues that divide Human Being Theorists who oppose embryo research from Person Theorists who favor embryo research. Higher order potential personhood is transitive if it is active, identity preserving and morally relevant. If the transition from the Second Order Potential of the embryo to the First Order Potential of an infant is transitive, opponents of embryo research make a powerful case for the moral status of the embryo. If it is (...) intransitive, then the Person Theorist can draw lines between levels of moral status that permit embryo research to proceed. (shrink)

Assigning the appropriate moral status to different stages of human development is an urgent problem in bioethics. Many philosophers have attempted to assess developmental events using strict ontological principles to determine when a developing entity becomes essentially human. This approach is not consistent with recent findings in reproductive and stem cell biology, including the discovery of the plasticity of early embryonic development and the advent of induced pluripotent stem cells. Substance ontology should therefore not be used to determine the moral (...) status of the embryo. (shrink)

The process of embryogenesis poses numerous philosophical puzzles. Conceptual difficulties encountered while attempting to clarify the ontological and moral status of the fertilized ovum, for example, are compounded in the minds of some philosophers by the possible occurrence of monozygotic twinning during the earliest stages of embryological development. In light of certain conceptual complexities engendered by this possibility, G.E.M. Anscombe, for example, has come to believe that the pivotal metaphysical query in need of an adequate response is the following: Is (...) the human zygote a single human? The answer to this question is of interest to Anscombe primarily for the role it would play in solving the following puzzle: Suppose that zygote A divides into twins B and B1, such that neither B nor B1 is identical with its twin or with A. It then seems clear that either A, prior to its division, was somehow already B and B1; or A was a single human out of which another human grew ; or A, which was a single human, became two humans, much like an amoeba becomes two amoebae; or A is a "whole human substantial entity". (shrink)

The author reviews one of the more intriguing articles in the stem cell research issue of the journal Metaphilosophy (April 2007), “Killing Embryos for Stem Cell Research,” by Jeff McMahan. He begins by recapitulating McMahan’s argument against the proposition that we are essentially individual human organisms. He then turns to two main critiques of the argument. First, he shows that the term “essentially” is insufficiently defined by McMahan and, more important, if we take the typical explication of the concept by (...) modal metaphysicians, then the claim “we are essentially human beings” is true—contrary to McMahan’s argument. Second, the author offers a counterexample to McMahan’s implicit acceptance of the principle that only beings who have developed the capacity for self-consciousness are the proper subjects of moral worth. The author presents a regenerative therapy example to show that McMahan’s commitment on this point is counterintuitive. National Catholic Bioethics Quarterly 8.2 (Summer 2008): 255–264. (shrink)

Howsepian has presented a number of thought experiments, which are designed to undermine my claim that our identity through time is grounded in the continued existence of those structures in our brains which directly underlie mental functioning. I argue that the conclusions which Howsepian draws from these thought experiments are mistaken, and that his discussion of them is vitiated, in particular, by his failure to distinguish between personal identity and the identity of the associated human organism.