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)

It may soon be possible to generate human organs inside of human-pig chimeras via a process called interspecies blastocyst complementation. This paper discusses what arguably the central ethical concern is raised by this potential source of transplantable organs: that farming human-pig chimeras for their organs risks perpetrating a serious moral wrong because the moral status of human-pig chimeras is uncertain, and potentially significant. Those who raise this concern usually take it to be unique to the creation of chimeric animals with (...) ‘humanised’ brains. In this paper, we show how that the same style of argument can be used to critique current uses of non-chimeric pigs in agriculture. This reveals an important tension between two common moral views: that farming human-pig chimeras for their organs is ethically concerning, and that farming non-chimeric pigs for food or research is ethically benign. At least one of these views stands in need of revision. (shrink)

Humans often seek to improve themselves, whether through self-discipline or through the use of science and technology. At some point in the future, techniques might become available that will change humans to such a degree that they might have to be regarded as something other than human: posthuman. This essay tries to define the point at which such a human-to-posthuman metamorphosis may occur. This is achieved by discerning what is it that makes human substance distinct, i.e. what is the human (...) essence. This is accomplished by examining the features of the human body, looking at the mode of human existence in society and trying to grasp the importance of the body–soul relationship. Throughout the process, humans are compared to animals as well as entities from literature, film, and the gaming world. These are used as case studies to shape and test the ideas developed throughout the essay. This essay's conclusions might become useful when decisions will have to be made as to the legal status of posthumans,... (shrink)