Human neural organoid research is advancing rapidly. As Greely notes in the target article, this progress presents an “onrushing ethical dilemma.” We can’t rule out the possibility that suff...

This chapter draws on insights from non-equilibrium thermodynamics to demonstrate the ontological inadequacy of the machine conception of the organism. The thermodynamic character of living systems underlies the importance of metabolism and calls for the adoption of a processual view, exemplified by the Heraclitean metaphor of the stream of life. This alternative conception is explored in its various historical formulations and the extent to which it captures the nature of living systems is examined. Following this, the chapter considers the metaphysical (...) implications of reconceptualizing the organism from complex machine to flowing stream. What do we learn when we reject the mechanical and embrace the processual? Three key lessons for biological ontology are identified. The first is that activity is a necessary condition for existence. The second is that persistence is grounded in the continuous self-maintenance of form. And the third is that order does not entail design. (shrink)

I argue against theories that attempt to reduce scientific representation to similarity or isomorphism. These reductive theories aim to radically naturalize the notion of representation, since they treat scientist's purposes and intentions as non-essential to representation. I distinguish between the means and the constituents of representation, and I argue that similarity and isomorphism are common but not universal means of representation. I then present four other arguments to show that similarity and isomorphism are not the constituents of scientific representation. I (...) finish by looking at the prospects for weakened versions of these theories, and I argue that only those that abandon the aim to radically naturalize scientific representation are likely to be successful. (shrink)

Human cerebral organoids are three-dimensional biological cultures grown in the laboratory to mimic as closely as possible the cellular composition, structure, and function of the corresponding organ, the brain. For now, cerebral organoids lack blood vessels and other characteristics of the human brain, but are also capable of having coordinated electrical activity. They have been usefully employed for the study of several diseases and the development of the nervous system in unprecedented ways. Research on human cerebral organoids is proceeding at (...) a very fast pace and their complexity is bound to improve. This raises the question of whether cerebral organoids will also be able to develop the unique feature of the human brain, consciousness. If this is the case, some ethical issues would arise. In this article, we discuss the necessary neural correlates and constraints for the emergence of consciousness according to some of the most debated neuroscientific theories. Based on this, we consider what the moral status of a potentially conscious brain organoid might be, in light of ethical and ontological arguments. We conclude by proposing a precautionary principle and some leads for further investigation. In particular, we consider the outcomes of some very recent experiments as entities of a potential new kind. (shrink)

My paper builds on the conceptual tools from three interrelated philosophical debates that—as I believe—may help structure important if chaotic discussions about surrogates for living human brains and resolve some practical issues related to regulatory matters. In particular, I refer to the discussions about the “moral precautionary principle” in research ethics (Koplin and Wilkinson 2019); about normative uncertainty in ethics (MacAskill, Bykvist, and Ord 2020), and about the inductive risk problem for animal welfare scientists (Birch 2018). I elucidate upon the (...) possible meanings of the phrase “a too good human brain surrogate” used by Henry T. Greely (2021), and I demonstrate that the evaluation of the practical and regulatory implications of the “goodness” of such surrogates created for research purposes should be sensitive to the possible consequences of two types of errors: the under-attribution and over-attribution of moral status to such beings. Many authors writing about this topic (including Greely 2021, but see also, e.g., Koplin and Savulescu 2019) concentrate only on the first type of error, neglecting the negative consequences of the second type, i.e., over-attribution. (shrink)

Consciousness-based approaches to non-human moral status maintain that consciousness is necessary for (some degree or level of) moral status. While these approaches are intuitive to many, in this paper I argue that the judgment that consciousness is necessary for moral status is not secure enough to guide policy regarding non-humans, that policies responsive to the moral status of non-humans should take seriously the possibility that psychological features independent of consciousness are sufficient for moral status. Further, I illustrate some practical consequences (...) of calling consciousness-based views into question. (shrink)

In this interesting paper, Lavazza and Massimini draw attention to a subset of the ethical issues surrounding the development and potential uses of cerebral organoids. This subset concerns the possibility that cerebral organoids may one day develop phenomenal consciousness, and thereby qualify as conscious subjects—that there may one day be something it is like to be an advanced cerebral organoid. This possibility may feel outlandish. But as Lavazza and Massimini demonstrate, the science of organoids is moving fast, and I agree (...) that the ethical issues now deserve careful scrutiny. The ethical issues are not entirely separate from epistemological issues concerning how certain we could ever be that an organoid is conscious or that regarding any conscious state or process, an organoid is capable of tokening that state or undergoing that process. Lavazza and Massimini’s approach is theory-based—they claim that ‘we need a general theory of consciousness that attempts to explain what experience is and what type of physical systems can have it’. I am not convinced, however, that a theory of consciousness is what we need. Nor am I convinced that detecting the presence of consciousness is the most important moral issue. Let me say a word regarding theories of consciousness first. In general, to the extent that pervasive disagreement characterises expert discussion of some phenomenon P, one should modify one’s credence downward regarding any theory of the nature of P. In my view, this is the case regarding expert discussion of consciousness. Although most philosophers are confident that consciousness is an entirely physical phenomenon, a …. (shrink)

This article proposes a methodological schema for engaging in a productive discussion of ethical issues regarding human brain organoids, which are three-dimensional cortical neural tissues created using human pluripotent stem cells. Although moral consideration of HBOs significantly involves the possibility that they have consciousness, there is no widely accepted procedure to determine whether HBOs are conscious. Given that this is the case, it has been argued that we should adopt a precautionary principle about consciousness according to which, if we are (...) not certain whether HBOs have consciousness—and where treating HBOs as not having consciousness may cause harm to them—we should proceed as if they do have consciousness. This article emphasizes a methodological advantage of adopting the precautionary principle: it enables us to sidestep the question of whether HBOs have consciousness and, instead, directly address the question of what kinds of conscious experiences HBOs can have, where the what-kind-question is more tractable than the whether-question. By addressing the what-kind-question, we will be able to examine how much moral consideration HBOs deserve. With this in mind, this article confronts the what-kind-question with the assistance of experimental studies of consciousness and suggests an ethical framework which supports restricting the creation and use of HBOs in bioscience. (shrink)

Human cerebral organoids (HCOs) are three-dimensional in vitro cell cultures that mimic the developmental process and organization of the developing human brain. In just a few years this technique has produced brain models that are already being used to study diseases of the nervous system and to test treatments and drugs. Currently, HCOs consist of tens of millions of cells and have a size of a few millimeters. The greatest limitation to further development is due to their lack of vascularization. (...) However, recent research has shown that human cerebral organoids can manifest the same electrical activity and connections between brain neurons and EEG patterns as those recorded in preterm babies. All this suggests that, in the future, HCOs may manifest an ability to experience basic sensations such as pain, therefore manifesting sentience, or even rudimentary forms of consciousness. This calls for consideration of whether cerebral organoids should be given a moral status and what limitations should be introduced to regulate research. In this article I focus particularly on the study of the emergence and mechanisms of human consciousness, i.e. one of the most complex scientific problems there are, by means of experiments on HCOs. This type of experiment raises relevant ethical issues and, as I will argue, should probably not be considered morally acceptable. (shrink)

In his interesting commentary, Joshua Shepherd raises two points—one related to epistemology, the other to ethics—about our article on human cerebral organoids.1 2 From the epistemological standpoint, he calls into question the need for a theory of consciousness. A theory of consciousness, for him, is not necessary because of the lack of consensus about the very nature of consciousness. Shepherd suggests that ‘given widespread disagreement, applying a theory of consciousness may not be helpful when attempting to diagnose the presence of (...) consciousness in cerebral organoids’. In Shepherd’s view, it would be better to transfer ‘concepts already under development in work on the presence and structure of consciousness in difficult marginal cases involving traumatic brain injury’.2 We could not agree more on this last point; detecting a minimal capacity for consciousness in the brain of comatose patients is a very similar challenge to inferring the presence of consciousness in cerebral organoids. Every day, as a by-product of saving many lives, intensive care medicine artificially produces thousands of brains that may remain isolated, split or fragmented; in the worst case, cortical islands, or an archipelago of islands, may survive while being disconnected from the outside world. Can these islands host some form of consciousness? That is, does it feel like anything to be a large piece of human cortex? Addressing this difficult question requires the development of general, objective brain-based indices of consciousness that are independent of sensory processing, executive functions and motor outputs.3 Consider, for example, a patient showing reflexive spontaneous behaviour, no response to command and no ability to communicate. In her brain, afferent pathways are damaged, thereby impairing the recruitment of cortical areas in response to sensory stimulation; basal ganglia, as well as other frontal structures supporting executive functions, are impaired. However, resting metabolism and significant electroencephalography …. (shrink)

Brain organoid research raises ethical challenges not seen in other forms of stem cell research. Given that brain organoids partially recapitulate the development of the human brain, it is plausible that brain organoids could one day attain consciousness and perhaps even higher cognitive abilities. Brain organoid research therefore raises difficult questions about these organoids' moral status – questions that currently fall outside the scope of existing regulations and guidelines. This paper shows how these gaps can be addressed. We outline a (...) moral framework for brain organoid research that can address the relevant ethical concerns without unduly impeding this important area of research. (shrink)

Is the mammalian embryo/fetus a part of the organism that gestates it? According to the containment view, the fetus is not a part of, but merely contained within or surrounded by, the gestating organism. According to the parthood view, the fetus is a part of the gestating organism. This paper proceeds in two stages. First, I argue that the containment view is the received view; that it is generally assumed without good reason; and that it needs substantial support if it (...) is to be taken seriously. Second, I argue that the parthood view derives considerable support from a range of biological and physiological considerations. I tentatively conclude in favour of the parthood view, and end by identifying some of the interesting questions it raises. (shrink)

Human brain research is moving into a dilemma. The best way to understand how the human brain works is to study living human brains in living human beings, but ethical and legal standards make it d...

The central task of cognitive neuroscience to map cognitive capacities to neural mechanisms faces three interlocking conceptual problems that together frame the problem of cognitive ontology. First, they must establish which tasks elicit which cognitive capacities, and specifically when different tasks elicit the same capacity. To address this operationalization problem, scientists often assess whether the tasks engage the same neural mechanisms. But to determine whether mechanisms are of the same or different kinds, we need to solve the abstraction problem by (...) determining which mechanistic differences are and are not relevant, and also the boundary problem by distinguishing the mechanism from its background conditions. Solving these problems, in turn, requires understanding how cognitive capacities are elicited in tasks. These three problems, which have been noted and discussed elsewhere in the literature, together form a ‘cycle of kinds’ that frames the central problem-space of cognitive ontology. We describe this cycle to clarify the intellectual challenges facing the cognitive ontologist and to reveal the kind of iterative process by which ontological revision in cognitive neuroscience is likely to unfold. (shrink)

The possibility that human cerebral organoids (HCOs) develop consciousness is one of the main concerns driving current ethical discourse. Evaluating existing evidence, Zilio and Lavazza (2023) in t...

Uncovering the neural basis of consciousness is a major challenge to neuroscience. In this Perspective, Tononi and colleagues describe the integrated information theory of consciousness and how it might be used to answer outstanding questions about the nature of consciousness.