Animal models of human diseases are often used in biomedical research in place of human subjects. However, results obtained by animal models may fail to hold true for humans. One way of addressing this problem is to make animal models more similar to humans by placing human tissue into animal models, rendering them chimeric. Since technical and ethical limitations make neurological disorders difficult to study in humans, chimeric models with human neural tissue could help advance our understanding of neuropathophysiology. In (...) this article, we examine whether the introduction of human neural tissue and any consequent cognitive change is relevant to the way we ought to treat chimeras. We argue that changes in cognitive abilities are morally relevant to the extent that they increase the capacities that affect the moral status of any entity, including awareness, autonomy, and sociability. We posit that no being, regardless of species, should be treated in a way that is incommensurate with its moral status. Finally, we propose a framework that can be used to guide ethical assessment of research involving chimeras with advanced cognitive capacities. We advance this framework as a useful tool for bringing relevant considerations to the forefront for those considering the ethical merit of proposed chimeric research. In doing so, we examine concepts relevant to the question of how any entity may be treated, including moral status, dignity, and capacities. (shrink)

The burgeoning field of biomedical research involving the mixture of human and animal materials has attracted significant ethical controversy. Due to the many dimensions of potential ethical conflict involved in this type of research, and the wide variety of research projects under discussion, it is difficult to obtain an overview of the ethical debate. This paper attempts to remedy this by providing a systematic review of ethical reasons in academic publications on human-animal chimera research. We conducted a systematic review of (...) the ethical literature concerning human-animal chimeras based on the research question: “What ethical reasons have been given for or against conducting human-animal chimera research, and how have these reasons been treated in the ongoing debate?” Our search extends until the end of the year 2017, including MEDLINE, Embase, PhilPapers and EthxWeb databases, restricted to peer-reviewed journal publications in English. Papers containing ethical reasons were analyzed, and the reasons were coded according to whether they were endorsed, mentioned or rejected. Four hundred and thirty-one articles were retrieved by our search, and 88 were ultimately included and analyzed. Within these articles, we found 464 passages containing reasons for and against conducting human-animal chimera research. We classified these reasons into five categories and, within these, identified 12 broad and 31 narrow reason types.15% of the retrieved passages contained reasons in favor of conducting chimera research, while 85% of the passages contained reasons against it. The reasons against conducting chimera research fell into four further categories: reasons concerning the creation of a chimera, its treatment, reasons referring to metaphysical or social issues resulting from its existence and to potential downstream effects of chimera research. A significant proportion of identified passages fell under Category C. We hope that our results, in revealing the conceptual and argumentative structure of the debate and highlighting some its most notable tendencies and prominent positions, will facilitate continued discussion and provide a basis for the development of relevant policy and legislation. (shrink)

The prospect of creating and using human–animal chimeras and hybrids that are significantly human-like in their composition, phenotype, cognition, or behavior meets with divergent moral judgments: on the one side, it is claimed that such beings might be candidates for human-analogous rights to protection and care; on the other side, it is supposed that their existence might disturb fundamental natural and social orders. This paper tries to show that both positions are paradoxically intertwined: they rely on two kinds of species (...) arguments, “individual species arguments” and “group species arguments,” which formulate opposing demands but are conceptually interdependent. As a consequence, the existence of HACHs may challenge exactly those normative standards on which the protection of HACHs may eventually be based. This ethical paradox could constitute the ultimate source of the “moral confusion” that some authors have suspected HACHs to provoke. (shrink)

In her important and well-known discussion “On the Moral and Legal Status of Abortion,” Mary Anne Warren regrets that “it is not possible to produce a satisfactory defense of a woman’s right to obtain an abortion without showing that the fetus is not a human being, in the morally relevant sense.” Unlike some more cautious philosophers, Warren thinks that we can definitively demonstrate that the fetus is not a person. In this paper, Warren’s argument is critically examined with a focus (...) especially on the question of the foundation and the boundaries of the moral community. The fundamental thesis of the paper is that Warren’s approach is flawed for at least four reasons: (1) that being a person is not as obviously central to having full moral rights as Warren assumes, (2) that her exclusivism regarding moral status has dubious moral consequences independent of the abortion issue, (3) that it is not clear that a fetus is not a person, even on Warren’s own criteria, and (4) her criteria for personhood are themselves suspect. (shrink)

As the author of a book entitled The Nature of Human Persons: Metaphysics and Bioethics (Eberl 2020), one might reasonably expect me to lament Jennifer Blumenthal-Barby’s (2024) call to end the use...

David DeGrazia (2009) and Stuart Rachels (2011), among others, offer moral arguments in favor of adopting a vegetarian diet that have, they claim, broad appeal. Rather than relying on an account of animal rights or a particular ethical theory, these arguments rely on the moral principle that an extensive amount of pain requires moral justification. Since people do not need to eat meat in order to survive, the arguments conclude that the pain that animals experience in factory farming is unjustified. (...) I argue that these very same arguments support a more radical conclusion, namely, vegetarians morally should avoid eating vegetables from industrialized farming. Thus, if vegetarians are convinced by the moral arguments for vegetarianism offered by DeGrazia and Rachels, then they should be convinced, by analogous reasoning, that they should not eat vegetables from industrialized farming. (shrink)

Scientists will soon be able to grow human-transplantable organs in pigs. This paper focuses on the question of whether it is morally permissible to eat genetically altered pigs after harvesting their organs. Despite a lack of scholarly discussion of this question, the impetus for it is straightforward. There is no reason to think that peoples’ taste for pig will subside when scientists reach the point of being able to growing mature human organs inside them. In this paper, I argue that (...) there is a good reason why we should eat genetically altered pigs and currently no compelling reasons to the contrary. (shrink)

Developments in biological technology in the last few decades highlight the surprising and ever-expanding practical benefits of stem cells. With this progress, the possibility of combining human and nonhuman organisms is a reality, with ethical boundaries that are not readily obvious. These inter-species hybrids are of a larger class of biological entities called “chimeras.” As the concept of a human-nonhuman creature is conjured in our minds, either incredulous wonder or grotesque horror is likely to follow. This paper seeks to mitigate (...) those worries and demotivate reasonable concerns raised against chimera research, all the while pressing current ethical positions toward their plausible conclusions. -/- In service of this overall aim, first, I intend to show that chimeras are far less foreign and fantastic in light of recent research in the lab; second, I intend to show that anti-realist (so-called “constructivist”) commitments regarding species ontology render the species distinction (i.e., the divide between human and nonhuman) superfluous as a basis for ethical practice; and third, I discuss some prevailing dignity accounts regarding the practical ethics of the creation, research, and treatment of chimeras. Consequently I intend to show that the adoption of this particular set of views (constructivist ontology, capacity-based ethics) in conjunction with recent research ought to justify a parallel with what we accord to humans persons, and that trajectory allows for cases of moral permissibility. (shrink)