Potentiality and human embryos

Consideration of the potentiality of human embryos to develop characteristics of personhood, such as intellect and will, has figured prominently in arguments against abortion and the use of human embryos for research. In particular, such consideration was the basis for the call of the US President's Council on Bioethics for a moratorium on stem cell research on human embryos. In this paper, I critique the concept of potentiality invoked by the Council and offer an alternative account. In contrast to the Council's view that an embryo's potentiality is determined by definition and is not affected by external conditions that may prevent certain possibilities from ever being realized, I propose an empirically grounded account of potentiality that involves an assessment of the physical and decisional conditions that may restrict an embryo's possibilities. In my view, some human embryos lack the potentiality to become a person that other human embryos have. Assuming for the sake of argument that the potential to become a person gives a being special moral status, it follows that some human embryos lack this status. This argument is then used to support Gene Outka's suggestion that it is morally permissible to experiment on 'spare' frozen embryos that are destined to be destroyed.     

The human embryo: a scientist's point of view

...Thus, my judgement is that a human embryo is not a human person, and so we may do experiments on it which involve killing it. But my judgement is also that a human embryo has the potential to become a human being. The consequence of this attribute is that it imposes limits on the kinds of experiments which may be performed on human embryos. It is this which sets the boundaries. Experiments which may harm the embryo while still allowing it subsequently to realise its potential, and become a person, should not be permitted. It is the potentiality of the human embryo which governs our behaviour towards it. Its potential makes it special, and radically different from any other human tissue. This potential which the early embryo has means that great respect must always be accorded it, and great thought and care must surround any dealings with it....     

Two claims about potential human beings

It seems that at conception something is formed which, due to its genetic make-up, has the potentiality to develop into a full-blown human being. Many believe that in virtue of this potentiality, this organism, the human zygote or early embryo, has in instrinsic value which makes it wrong to use or produce it merely as a means to some end, e.g., some scientific end such as to produce embryonic stem cells. Against this it is here argued, first, that it does not follow from the fact that something has a potential to become a (fully developed) human being that it already is a human being (in a rudimentary sense). In fact, a human being begins to exist no earlier than a couple of weeks after conception, at the stage known as gastrulation. Thus, even granted the questionable assumption that something has instrinsic value in virtue of being a human being, the zygote will not have intrinsic value. Secondly, the value an embryo has in virtue of its potentiality to become a full-blown human being can only be instrumental, a value as a means. But of course it cannot be wrong to treat that which has merely instrumental value as a mere means or instrument to some end.     

The Concept of Human Dignity in the Ethics of Genetic Research

Despite criticism that dignity is a vague and slippery concept, a number of international guidelines on bioethics have cautioned against research that is contrary to human dignity, with reference specifically to genetic technology. What is the connection between genetic research and human dignity? In this article, I investigate the concept of human dignity in its various historical forms, and examine its status as a moral concept. Unlike Kant's ideal concept of human dignity, the empirical or relational concept takes human dignity as something that is affected by one's circumstances and what others do. I argue that the dignity objection to some forms of genetic research rests on a view of human nature that gives humans a special status in nature – one that is threatened by the potential of genetic research to reduce individuals to their genetic endowment. I distinguish two main philosophical accounts of human nature. One of these, the Aristotelian view, is compatible with the use of genetic technology to help humans realize their inherent potential to a fuller extent.     

Racialization: a defense of the concept

This paper defends the concept of racialization against its critics. As the concept has become increasingly popular, questions about its meaning and value have been raised, and a backlash against its use has occurred. I argue that when “racialization” is properly understood, criticisms of the concept are unsuccessful. I defend a definition of racialization and identify its companion concept, “racialized group.” Racialization is often used as a synonym for “racial formation.” I argue that this is a mistake. Racial formation theory is committed to racial ontology, but racialization is best understood as the process through which racialized – rather than racial – groups are formed. “Racialization” plays a unique role in the conceptual landscape, and it is a key concept for race eliminativists and anti-realists about race.     

The expansion of information in ecological systems: Emergence as a quantifiable state

Although the term ‘emergence’ has received wide attention in the literature, most of this attention has been focused on epistemological discussions about the nature of what might be considered emergent behavior in self-organizing systems. For the concept of emergence to have any great utility for biologists, it must (1) be perceptible as a physical, quantitative property rather than just a philosophical one; (2) have a quantitative definition applicable to all levels of biological organization; and (3) be an essential component of biological system performance or evolution. Using an independent, cellular population model (running in the StarLogo system), we have developed a mutual information calculation to measure the information expansion when considering the interactions between a population of herbivores and an environment in comparison to the interactions between the individual herbivores and that environment. In self-organizing biological systems, the collective action of massively parallel units generates a greater potential complexity in the information processing capacity of the ‘whole’ system relative to the ‘individual’ parts, and as such, there is a demonstrable increase in mutual information content. From this perspective, we consider emergence to exist as a simple information expansion that is a default behavior of any system with multiple, component parts governed by a simple, probabilistic rule set. It is not a first principle of self-organizing biological systems, but rather a collective behavior that can be quantitatively described in practical terms for experimental biologists. With a quantitative formulation, the concept of emergence may become a useful information statistic in assessing the structure of biological systems.     

On concept formation in systematics

In his “Grundzüge einer Theorie der phylogenetischen Systematik”, Hennig (1950 ) cited three philosophers: the leading empiricist Rudolf Carnap, the conventionalist Hugo Dingler, and the somewhat more obscure empiricist Theodor Ziehen. David Hull characterized Hennig's “Grundzüge” as one long argument against idealistic morphology. It will here be argued that Hennig attacked idealistic morphology (synonymous with “systematic” morphology) for its mode of concept formation. Building on Carnap and Ziehen, who both looked back on Ernst Cassirer, Hennig argued that the “generic”, “thing” or “class” concept of traditional nomothetic science must be replaced with Cassirer's “relation concept.” According to Hennig, such “emancipation” of systematics from the Aristotelian “species” concept would also allow transcendence from the distinction of idiographic from nomothetic sciences, thus preserving the unity of science. However, the establishment of relations in the construction of a system of order presupposes entities that can be, or are, related. Relations presuppose relata, which in modern systematics are best conceptualized (at least at the supraspecific level) not as Aristotelian classes, nor as individuals as was argued by Hennig and Ziehen, but as tokens of natural kinds. © The Willi Hennig Society 2006.     

A dark business,full of shadows: Analogy and theology in William Harvey

In a short work called De conceptione appended to the end of his Exercitationes de generatione animalium (1651), William Harvey developed a rather strange analogy. To explain how such marvelous productions as living beings were generated from the rather inauspicious ingredients of animal reproduction, Harvey argued that conception in the womb was like conception in the brain. It was mostly rejected at the time; it now seems a ludicrous theory based upon homonymy. However, this analogy offers insight into the structure and function of analogies in early modern natural philosophy. In this essay I hope to not only describe the complex nature of Harvey’s analogy, but also offer a novel interpretation of his use of analogical reasoning, substantially revising the account offered by Guido Giglioni (1993). I discuss two points of conceptual change and negotiation in connection with Harvey’s analogy, understanding it as both a confrontation between the border of the natural and the supernatural, as well as a moment in the history of psychology. My interpretation touches upon a number of important aspects, including why the analogy was rejected, how Harvey systematically deployed analogies according to his notions of natural philosophical method, how the analogy fits into contemporary discussions of analogies in science, and finally, how the analogy must be seen in the context of changing Renaissance notions of the science of the soul, ultimately confronting the problem of how to understand final causality in Aristotelian science. In connection with the last, I conclude the essay by turning to how Harvey embeds the analogy within a natural theological cosmology.     

The mechanism of heme oxygenase

Major advances have been made in determining the structure of heme oxygenase and the relationship between its structure and catalytic activity. The nature of the first step in the reaction sequence, heme alpha-meso-hydroxylation, is now clear, although the mechanisms that control the alpha-regiospecificity remain elusive. Hypothetical mechanisms can be written for the steps that convert alpha-meso-hydroxyheme to biliverdin, but these mechanisms must be validated before this complex reaction sequence can be fully understood. The salient conclusion appears to be that the heme-oxygenase reaction reflects the absence of interactions that channel the reaction towards a ferryl species, rather than the presence of interactions that specifically promote heme oxidation.     

Motility, Potentiality, and Infinity—A Semiotic Hypothesis on Nature and Religion

Against any obscurantist stand, denying the interest of natural sciences for the comprehension of human meaning and language, but also against any reductionist hypothesis, frustrating the specificity of the semiotic point of view on nature, the paper argues that the deepest dynamic at the basis of meaning consists in its being a mechanism of ??potentiality navigation?? within a universe generally characterized by motility. On the one hand, such a hypothesis widens the sphere of meaning to all beings somehow endowed with the capacity of moving and/or perceiving movement. On the other hand, through a new evolutionist interpretation of the concept of generativity, such a hypothesis preserves the peculiarity of human meaning, meant as essentially founded on a certain intuition of infinity. Two corollaries stem from this hypothesis: first, religiosity can be considered as a matrix of grammars of infinity, aiming at regimenting its flight of potentialities. Second, non-genetic transmission of cultural information exerts determinant influence also at the level of that very deep mechanism of the human predicament that is the cognitive navigation of motor potentialities. A re-reading of the structuralist epistemology, scientific literature on the nervous cells of jellyfish, and some recent experiments on the mirror neurons of dancers, as well as certain intuitions of Teilhard de Chardin, are the main arguments of the paper.     

Biocultural Diversity: Moving Beyond the Realm of ‘Indigenous’ and ‘Local’ People

During the past decade the relationship between biodiversity and human diversity has received increased attention, resulting in the identification of what the Declaration of Belém calls an ‘inextricable link’ between biological and cultural diversity. Although the term biocultural diversity, introduced to denote this link, is being used increasingly, there has been little critical reflection on what it precisely refers to. I argue that it is used with particular reference to ‘indigenous traditional’ people, but that there is scope for extending its application within biocultural discourse. I therefore review the concept of culture and discuss what constitutes cultural values of the natural environment. I conclude that the concept of culture must be understood as involving a dynamic process of transcultural exchange and constant re-articulations of tradition resulting in the persistence of certain cultural practices. This approach ultimately reveals that the concept of biocultural diversity is also applicable to non-indigenous traditional communities.     

Supportive or information-processing functions of the mature protoplasmic astrocyte in the mammalian CNS? A critical appraisal

It has been proposed that astrocytes should no longer be viewed purely as support cells for neurons, such as providing a constant environment and metabolic substrates, but that they should also be viewed as being involved in affecting synaptic activity in an active way and, therefore, an integral part of the information-processing properties of the brain. This essay discusses the possible differences between a support and an instructive role, and concludes that any distinction has to be blurred. In view of this, and a brief overview of the nature of the data, the new evidence seems insufficient to conclude that the physiological roles of mature astrocytes go beyond a general support role. I propose a model of mature protoplasmic astrocyte function that is drawn from the most recent data on their structure, the domain concept and their syncytial characteristics, of an independent rather than integrative functioning of the ends of each process where the activities that affect synaptic activity and blood vessel diameter will be concentrated.     

The elephant in the room - healthy brains in later life, epidemiology and public health

The increasing age of the population around the world has meant that greater attention is being paid to disorders that mainly affect older people. In particular, work is focusing on ways to preserve the healthy brain and prevent dementia. Preventive studies are complex and must take into account not only simple approaches such as those used in risk and outcome studies, but also stage of life, survival and mortality, and population context before their effect can be assessed. This paper presents questions and areas which must be explored if the potential for prevention of dementia during brain ageing is to be properly understood.     

WARNOCK VERSUS POWELL (AND HARRADINE): WHEN DOES POTENTIALITY COUNT?*

Lockwood's essay is one of three in this issue of Bioethics on potentiality and its applicability to research with human embryos. (See also Richard M. Hare's "When does potentiality count? A comment on Lockwood," and Stephen Buckle's "Arguing from potential.") The author critiques the reasoning behind some of the proposals for regulating such research, particularly the recommendations of Britain's Warnock Committee and Enoch Powell's legislative response, the Unborn Children (Protection) Bill. Lockwood attempts to formulate a logically defensible and morally plausible position on potentiality, arguing that it is potential plus identity, which depends on brain development, which generates moral claims. He concludes that, while there may be practical reasons for banning embryo research after the nervous system begins to develop, it may not be morally wrong to experiment with miscarried fetuses whose brain is developing, but who are nonviable.     

The Issues of Freedom and Happiness in Moral Bioenhancement: Continuing the Debate With a Reply to Harris Wiseman

During the previous years, Harris Wiseman has devoted substantial attention to my stance on voluntary moral bioenhancement. He argued that he has been influenced by that position, but nonetheless criticized it. I haven’t replied to his criticisms yet and wish to do so now. One of the reasons is to avoid my position being misrepresented. By replying to Wiseman’s criticisms, I also wish to clarify those issues in my standpoint that might have given rise to some of the misinterpretations. With the same purpose in mind, I will demarcate my concept of voluntary moral bioenhancement from related standpoints, in particular from Persson and Savulescu’s notion of compulsory moral bioenhancement that, as I argued, diminishes our freedom (of the will). Furthermore, I will consider the possibility of adding another essential element to my position—one that I have not discussed in my earlier publications. It is designed to propose a novel explanation of why humans would be motivated to opt for voluntary moral bioenhancement if its outcome is not a lowering of the likelihood of “Ultimate Harm” (as defined by Persson and Savulescu) or a milder form of self-destruction of humanity. This explanation will be based on the conception that an increase in happiness, rather than Ultimate Harm prevention, might be the grounding rationale for moral bioenhancement.     

In defence of the high energy phosphate bond

The concept of the “high energy phosphate bond” has recently been strongly criticised by Banks &; Vernon. The criticisms were: (i) energy cannot be stored in molecules; let alone in bonds; (ii) a muscle is an open system, so that the free energy of hydrolysis of ATP is irrelevant; (iii) biological reactions cannot be at equilibrium, therefore they must be inefficient. It is argued that all of these criticisms arise because the timescale appropriate to molecular events has been left out; in particular “stored energy” needs to be defined relative to the machine which uses that energy. The criticisms may be answered using a conceptual framework which overcomes this deficiency and which was developed previously to extend classical thermodynamics to the molecular level. Criticism (i) is refuted by discussing in detail the chemiluminescent reaction of rubrene oxide, which can only be described as liberating internal energy stored in a single molecule; while it is true that entropy cannot be retained in a single molecule for long enough to do useful work with it, there is nothing which forbids internal energy from being so stored. Criticism (ii) would be true if, and only if, a muscle uses the same kind of mechanism as do the ordinary chemical machines with which we are familiar (batteries, etc). But this assumption is shown to be false; a muscle cannot use this type of mechanism. Criticism (iii) is answered by finding the conditions under which a biological machine could in fact approach 100% efficiency. These conditions are: (i) in metabolism ΔF = 0; the steps are in thermal equilibrium; (ii) in the molecular machines themselves ΔS = 0, so that ΔF = ΔH; the machines are mechanical. It is also shown that not only are these conditions perfectly conceivable, but also that there is good evidence that, over the course of evolution, they have actually been attained.     

The importance of phase information for human genomics

Contemporary sequencing studies often ignore the diploid nature of the human genome because they do not routinely separate or 'phase' maternally and paternally derived sequence information. However, many findings - both from recent studies and in the more established medical genetics literature - indicate that relationships between human DNA sequence and phenotype, including disease, can be more fully understood with phase information. Thus, the existing technological impediments to obtaining phase information must be overcome if human genomics is to reach its full potential.     

三种愈伤组织中质体的DNA含量变化及其与水稻花粉白苗形成的关系

以质体为单位的愈伤组织ptDNA的荧光强度变化显示出了特有的规律性,结合光培养花粉白苗叶质体结构的电镜观察及叶绿素等色素的测定等,这种规律性似提示花粉白苗的ptDNA由于发生了相继缺失而显示出高度异质性,花粉白苗的形成则在于其占优势ptDNA的严重缺失,花粉白苗ptDNA的这种相继缺失不是随机的,似反映了ptDNA顺序组织上的特点,故ptDNA发生缺失的潜在可能性具有普遍意义,它与父系细胞质体类核的消失存在着并行关系,花粉白苗的占优势ptDNA指导的植株的性状,而次要ptDNA亦在较小程度上显示出影响。     

What is life? Prerequisites for a definition

Biologists view life as transient while theologians see it as eternal. An unbiased definition for life would respect both views until one or both were eliminated by evidence. This paper identifies pre-requisites for such a definition. First among these is that all assumptions be made explicit. Currently "life" is surrounded by implicit assumptions, e.g., that it is what organisms lose at death or that it is eternal, that its quality is inversely related to personal distress, that it originated some four billion years ago, and that animate matter can be distinguished from inanimate matter. None of these assumptions are supported by data. It is possible therefore that "life" is as meaningless as phlogiston. If life has meaning, i.e., if it is true, it must be as permanent as buoyancy, gravity, electricity, and the other truths of nature. Any definition for life that would permit such truth to be seen must be free of unwarranted assumptions. For the moment, at least, such a definition would need to be loosely structured and broadly focused. It would need to describe the long and convoluted process by which matter and energy form organisms which then evolve to form conscious organisms which then explore nature and eventually discover truth. Such a definition would include all the reactions and interactions of matter and energy and all the aspects of conscious discovery. It would suffer from superficiality, but, by being free from bias, provide a foundation for dialogue between biologists and theologians.     

Structure-activity relationship of amyloid fibrils

Protein aggregation is a process in which proteins self-associate into imperfectly ordered macroscopic entities. Such aggregates are generally classified as either amorphous or highly ordered, the most common form of the latter being amyloid fibrils. Amyloid fibrils composed of cross-β-sheet structure are the pathological hallmarks of several diseases including Alzheimer’s disease, but are also associated with functional states such as the fungal HET-s prion. This review aims to summarize the recent high-resolution structural studies of amyloid fibrils in light of their (potential) activities. We propose that the repetitive nature of the cross-β-sheet structure of amyloids is key for their multiple properties: the repeating motifs can translate a rather non-specific interaction into a specific one through cooperativity.