Abstract The only biologically respectable notion of human nature is an extremely permissive one that names the reliable dispositions of the human species as a whole. This conception offers no ethical guidance in debates over enhancement, and indeed it has the result that alterations to human nature have been commonplace in the history of our species. Aristotelian conceptions of species natures, which are currently fashionable in meta-ethics and applied ethics, have no basis in biological fact. Moreover, because our folk psychology (...) finds this misleading Aristotelian conception highly tempting, we are in fact better off if we refrain from mentioning human nature altogether in debates over enhancement. Content Type Journal Article Category Special Issue Pages 1-16 DOI 10.1007/s13347-012-0063-x Authors Tim Lewens, Department of History and Philosophy of Science, University of Cambridge, Free School Lane, Cambridge, CB2 3RH UK Journal Philosophy & Technology Online ISSN 2210-5441 Print ISSN 2210-5433. (shrink)

Philosophers of biology, such as David Hull and Michael Ghiselin, have argued that the notion of human nature is incompatible with modern evolutionary biology and they have recommended rejecting this notion. In this article, I rebut this argument: I show that an important notion of human nature is compatible with modern evolutionary biology.

Appeals to the idea of human nature are frequent in the voluminous literature on the ethics of enhancing human beings through biotechnology. Two chief concerns about the impact of enhancements on human nature have been voiced. The first is that enhancement may alter or destroy human nature. The second is that if enhancement alters or destroys human nature, this will undercut our ability to ascertain the good because, for us, the good is determined by our nature. The first concern assumes (...) that altering or destroying human nature is in itself a bad thing. The second concern assumes that human nature provides a standard without which we cannot make coherent, defensible judgments about what is good. I will argue (1) that there is nothing wrong, per se, with altering or destroying human nature, because, on a plausible understanding of what human nature is, it contains bad as well as good characteristics and there is no reason to believe that eliminating some of the bad would so imperil the good as to make the elimination of the bad impermissible, and (2) that altering or destroying human nature need not result in the loss of our ability to make judgments about the good, because we possess a conception of the good by which we can and do evaluate human nature. I will argue that appeals to human nature tend to obscure rather than illuminate the debate over the ethics of enhancement and can be eliminated in favor of more cogent considerations. (shrink)

I develop and refine an argument for the total brain death criterion of death previously advanced by Germain Grisez and me: A human being is essentially a rational animal, and so must have a radical capacity for rational operations. For rational animals, conscious sensation is a pre-requisite for rational operation. But total brain death results in the loss of the radical capacity for conscious sensation, and so also for rational operations. Hence, total brain death constitutes a substantial change—the ceasing to (...) be of the human being. Objections are considered, including the objection that total brain death need not result in the loss of capacity for sensation, and that damage to the brain less than total brain death can result in loss of capacity for rational operations. (shrink)

This article explains the problems with Alan Shewmon’s critique of brain death as a valid sign of human death, beginning with a critical examination of his analogy between brain death and severe spinal cord injury. The article then goes on to assess his broader argument against the necessity of the brain for adult human organismal integration, arguing that he fails to translate correctly from biological to metaphysical claims. Finally, on the basis of a deeper metaphysical analysis, I offer a revised (...) rationale for the validity of the neurological criterion of human death. (shrink)

Appeals to the idea of human nature are frequent in the voluminous literature on the ethics of enhancing human beings through biotechnology. Two chief concerns about the impact of enhancements on human nature have been voiced. The first is that enhancement may alter or destroy human nature. The second is that if enhancement alters or destroys human nature, this will undercut our ability to ascertain the good because, for us, the good is determined by our nature. The first concern assumes (...) that altering or destroying human nature is in itself a bad thing. The second concern assumes that human nature provides a standard without which we cannot make coherent, defensible judgments about what is good.I will argue (1) that there is nothing wrong, per se, with altering or destroying human nature, because, on a plausible understanding of what human nature is, it contains bad as well as good characteristics and there is no reason to believe that eliminating some of the bad would so imperil the good as to make the elimination of the bad impermissible, and (2) that altering or destroying human nature need not result in the loss of our ability to make judgments about the good, because we possess a conception of the good by which we can and do evaluate human nature. I will argue that appeals to human nature tend to obscure rather than illuminate the debate over the ethics of enhancement and can be eliminated in favor of more cogent considerations. (shrink)

Neurotechnologies that promise to dampen (via pharmacologicals), disassociate (via electro-convulsive therapy), erase (via deep brain stimulation), and replace (via false memory creation) unsavory episodic memories are no longer the subject of science fiction. They have already arrived, and their funding suggests that they will not disappear anytime soon. In light of their emergence, this essay examines the neurostructure of normative morality to clarify that memory manipulation, which promises to take away that which is bad in human experience, also removes that (...) which enables human beings to be good. Concepts such as free will, moral responsibility, and the neurobiological basis of moral reasoning are explored to underscore the fundamental hubris inherent to the memory manipulation enterprise. (shrink)

Disorders of sexual differentiation lead to what is often referred to as an intersex state. This state has medical, as well as some legal, recognition. Nevertheless, the question remains whether intersex persons occupy a state in between maleness and femaleness or whether they are truly men or women. To answer this question, another important conundrum needs to be first solved: what defines sex? The answer seems rather simple to most people, yet when morphology does not coincide with haplotypes, and genetics (...) might not correlate with physiology the issue becomes more complex. This paper tackles both issues by establishing where the essence of sex is located and by superimposing that framework onto the issue of the intersex. This is achieved through giving due consideration to the biology of sexual development, as well as through the use of a teleological framework of the meaning of sex. Using a range of examples, the paper establishes that sex cannot be pinpointed to one biological variable but is rather d... (shrink)

Human life is operationally defined by the onset and cessation of organismal function. At postnatal stages of life, organismal integration critically and uniquely requires a functioning brain. In this article, a distinction is drawn between integrated and coordinated biologic activities. While communication between cells can provide a coordinated biologic response to specific signals, it does not support the integrated function that is characteristic of a living human being. Determining the loss of integrated function can be complicated by medical interventions that (...) uncouple elements of the natural biologic hierarchy underlying our intuitive understanding of death. Such medical interventions can allow living human beings who are no longer able to function in an integrated manner to be maintained in a living state. In contrast, medical intervention can also allow the cells and tissues of an individual who has died to be maintained in a living state. To distinguish between a living human being and living human cells, two criteria are proposed: either the persistence of any form of brain function or the persistence of autonomous integration of vital functions. Either of these criteria is sufficient to determine a human being is alive. (shrink)

Neuroscience and technological medicine in general increasingly faces us with the imminent reality of cyborgs—integrated part human and part machine complexes.If my brain functions in a way that is supported by and exploits intelligent technology both external and implantable, then how should I be treated and what is my moral status—am I a machine or am I a person? I explore a number of scenarios where the balance between human and humanoid machine shifts, and ask questions about the moral status (...) of the individuals concerned. The position taken is very much in accordance with the Aristotelian idea that our moral behaviour is of a piece with our social and personal skills and forms a reactive and reflective component of those skills. (shrink)

We see in the early texts of Marx a continuity of thought, where the individual essence of man is likewise regarded to be social. This concept is for Marx not abstract; that is, it is not to be understood in isolation from nature or other men.

The mainstream rationale for equating brain death (BD) with death is that the brain confers integrative unity upon the body, transforming it from a mere collection of organs and tissues to an organism as a whole. In support of this conclusion, the impressive list of the brains myriad integrative functions is often cited. Upon closer examination, and after operational definition of terms, however, one discovers that most integrative functions of the brain are actually not somatically integrating, and, conversely, most integrative (...) functions of the body are not brain-mediated. With respect to organism-level vitality, the brains role is more modulatory than constitutive, enhancing the quality and survival potential of a presupposedly living organism. Integrative unity of a complex organism is an inherently nonlocalizable, holistic feature involving the mutual interaction among all the parts, not a top-down coordination imposed by one part upon a passive multiplicity of other parts. Loss of somatic integrative unity is not a physiologically tenable rationale for equating BD with death of the organism as a whole. (shrink)

During the battle of Iwo Jima in June 1944, Private First Class Jackylin Harold Lucas and three other U.S. Marines came under attack while making their way along a ravine. Upon seeing two grenades thrown near the soldiers, Lucas dove onto one grenade and pulled the other under his body, saving his companions from serious injury or death. Lucas survived, but his injuries were so grave that his companions left him for dead. Lucas’s act was one of spectacular and nearly (...) suicidal altruism. What does such an act show us about our nature and the human capacity for good and evil? Perhaps it offers a window onto our true nature—a nature ultimately good, though susceptible to corrupting influences. Or perhaps it seems extraordinary precisely because we are greedy and violent by nature but can, in rare instances, rise above those instincts. Questions about what human nature is and how we can learn about it are difficult to answer. They are difficult not just because humans are complex creatures whose behavior is deeply embedded in the cultural environment that they are a part of, but also because it is not obvious what a concept of human nature is supposed to do or what it is for. The concept of human nature is often used as a normative concept, one that can serve as a guide to action, showing us how we ought to behave. Less commonplace is an approach that seeks a descriptive account of human nature, one that characterizes what humans do and are disposed to do. I argue in this essay that the normative and descriptive approaches are at odds and that we should not expect a single concept of human nature to play both roles. Furthermore, there are deep problems with normative accounts. They often ignore or contradict the contemporary scientific worldview, and they often merely reflect biases about how we ought to be and what we ought to do. Human nature in this sense becomes politicized and serves in arguments about the moral status of issues like homosexuality, abortion, or biomedical enhancement. Because of the problems inherent in normative notions of human nature, I offer a descriptive alternative. My alternative attempts to align the scientific study of the human with human nature. (shrink)

The principal focus of this paper is to consider the implications of head and neck transplantation surgery on the issue of personal identity. To this end, it is noted that the immune system has not only been established to impose a level of self-identity on bodily cells, it has also been implicated in mental development and the regulation of mental state. In this it serves as a paradigm for the mind as the product of cephalic and extracephalic systems. The importance (...) of bodily systems in identity is then discussed in relation to phantom tissue syndrome. The data strongly indicate that, even if surgically successful, head and neck transplantation will result in the loss of the continuity of personal identity. (shrink)

In this commentary on Lewens, I argue that although his criticisms of Machery's conception of human nature are sound, I disagree with his conclusion that human nature cannot inform us regarding issues of human enhancement. I introduce a framework for understanding human nature, the “life history trait cluster account,” which aligns the concept of human nature with the human sciences and allows human nature to inform questions of human enhancement.

This is a transcription of a debate on the concept of a person conducted in Moscow in 1983. David Bakhurst argues that Evald Ilyenkov's social constructivist conception of personhood, founded on Marx's thesis that the human essence is the ensemble of social relations, is either false or trivially true. F. T. Mikhailov, V. S. Bibler, V. A. Lektorsky and V. V. Davydov critically assess Bakhurst's arguments, elucidate and contextualize Ilyenkov's views, and defend, in contrasting ways, the claim that human individuals (...) are socially constituted beings. Issues discussed include: the concepts of activity (dejatel'nost') and community (obenija) and their relevance to the notions of mind and personhood; self-consciousness and its relation to personal identity; naturalism in Soviet thought. Translated from the Russian. (shrink)

This statement summarizes the conclusions of the Symposium on the Definition of Death, held at The Catholic University of America in June 2014. After providing the background and context for contemporary debates about brain death and describing the aims of the symposium, the statement notes points of unanimous and broad agreement among the participants, and highlights areas for further study.

We see in the early texts of Marx a continuity of thought, where the individual essence of man is likewise regarded to be social. This concept is for Marx not abstract; that is, it is not to be understood in isolation from nature or other men.

: The transplantation of adult human neural stem cells into prenatal non-humans offers an avenue for studying human neural cell development without direct use of human embryos. However, such experiments raise significant ethical concerns about mixing human and nonhuman materials in ways that could result in the development of human-nonhuman chimeras. This paper examines four arguments against such research, the moral taboo, species integrity, "unnaturalness," and human dignity arguments, and finds the last plausible. It argues that the transfer of human (...) brain or retinal stem cells to nonhuman embryos would not result in the development of human-nonhuman chimeras that denigrate human dignity, provided such stem cells are dissociated. The article provides guidelines that set ethical boundaries for conducting such research that are consonant with the requirements of human dignity. (shrink)

Neurotechnologies that promise to dampen (via pharmacologicals), disassociate (via electro-convulsive therapy), erase (via deep brain stimulation), and replace (via false memory creation) unsavory episodic memories are no longer the subject of science fiction. They have already arrived, and their funding suggests that they will not disappear anytime soon. In light of their emergence, this essay examines the neurostructure of normative morality to clarify that memory manipulation, which promises to take away that which is bad in human experience, also removes that (...) which enables human beings to be good. Concepts such as free will, moral responsibility, and the neurobiological basis of moral reasoning are explored to underscore the fundamental hubris inherent to the memory manipulation enterprise. (shrink)

D. Alan Shewmon has advanced a well-documented challenge to the widely accepted total brain death criterion for death of the human being. We show that Shewmon's argument against this criterion is unsound, though he does refute the standard argument for that criterion. We advance a distinct argument for the total brain death criterion and answer likely objections. Since human beings are rational animals – sentient organisms of a specific type – the loss of the radical capacity for sentience involves a (...) substantial change, the passing away of the human organism. In human beings total brain death involves the complete loss of the radical capacity for sentience, and so in human beings total brain death is death. (shrink)

Research with human–animal chimera raises a number of ethical concerns, especially when neural stem cells are transplanted into the brains of non-human primates . Besides animal welfare concerns and ethical issues associated with the use of embryonic stem cells, the research is also regarded as controversial from the standpoint of NHPs developing cognitive or behavioural capabilities that are regarded as “unique” to humans. However, scientists are urging to test new therapeutic approaches for neurological diseases in primate models as they better (...) mimic human physiology than all current animal models. As a response, various countries have issued reports on the topic. Our paper summarizes the ethical issues raised by research with human–animal brain chimeras and compares the relevant regulatory instruments and different recommendations issued in national reports from three important European research nations: Germany, Switzerland and the United Kingdom. We assess and discuss the focus and priorities set by the different reports, review various reasons for and perspectives on the importance of the brain in chimera research, and identify critical points in the reports that warrant further specification and debate. (shrink)