This article addresses the theme of ‘death and immortality’ from the perspective of consciousness, and takes as its starting point a root text of Hindu philosophy, the Sāṃkhyakārikā by Īśvarakṛṣṇa (c. fourth century ce). The text posits a dualist ontology in which consciousness is separate and autonomous from a material reality that includes body and mind. The goal is to be ontologically situated in a ‘pure’ consciousness (non-objective), which signifies existential liberation. There are mundane ways to understand this claim, such as referring to cognitive states that produce affective dissociation, or more radical interpretations, such as a post-death state. This article explores the question of what Sāṃkhya's consciousness is like: it is said to be immortal, plural, individuated, and contentless. What is the motivation for and implication of engagement with a system that describes an existential freedom that may only be known in a dualist reality or after death? And how can Sāṃkhya's concepts be brought into conversation with contemporary investigations into mind–body questions? Sāṃkhya rationality counters the argument of eternal oblivion or of consciousness as an illusion confined to the brain. Yet there are resonances with Chalmers's notion of consciousness as fundamental. This article concludes that contemporary Anglo-American philosophy of religion can be enhanced by adding Sāṃkhya thought to its purview.

The risk of creating cerebral organoids/assembloids conscious enough to suffer is a recurrent concern in organoid research ethics. On one hand, we should, apparently, avoid discovering how to distinguish between organoids that it would be permissible (non-conscious) and impermissible (conscious) to use in research, since if successful we would create organoids that suffer. On the other, if we do not, the risk persists that research might inadvertently continue to cause organoids to suffer. Moreover, since modeling some brain disorders may require inducing stress in organoids, it is unclear how to eliminate the risk, if we want to develop effective therapies. We are committed to harm avoidance but hamstrung by a presumption that we should avoid research that might tell us clearly when suffering occurs. How can we negotiate this challenge and maximize the therapeutic benefits of cerebral organoid research? The author interrogates the challenge, suggesting a tentative way forward.

David Chalmers advocates the view that the phenomenon of consciousness is fundamentally different from all other phenomena studied in the life sciences, positing a uniquely hard problem that precludes the possibility of a mechanistic explanation. In this paper, I evaluate three demarcation criteria for dividing phenomena into hard and easy problems: functional definability, the puzzle of the accompanying phenomenon, and the first-person data of subjective experience. I argue that none of the proposed criteria can accurately discriminate between the phenomenon of consciousness and mechanistically explainable phenomena.

The possibility of consciousness in human brain organoids is sometimes viewed as determinative in terms of the moral status such entities possess, and, in turn, in terms of the research protections such entities are due. This commonsense view aligns with a prominent stance in neurology and neuroscience that consciousness admits of degrees. My paper outlines these views and provides an argument for why this picture of correlating degrees of consciousness with moral status and research protections is mistaken. I then provide an alternative account of the correlation between moral status and consciousness, and consider the epistemic ramifications for research protections of this account.

The contributions to this Special Issue examine multispecies perspectives on the political dynamics of international life. Building on this theme, I consider the complex and manifold ways in which the subject of security can be understood in terms of more-than-human personhood. First, by thinking of more-than-human animals as phenomenally conscious persons, we might better appreciate the multispecies complexity of security as an agentic and affective experience. Second, attending to the spiritual character of certain indigenous articulations of personhood presses us to decipher how spiritual claims might inform moral and legal dimensions of multispecies security-seeking behaviour. To illustrate the significance of these moves, I first draw on more-than-human experiences of war, pathogenic viruses, and the global factory farm. I then explore conceptions of spiritual personhood in the context of Ojibwe responsibilities to protect wolves. These perspectives on personhood demonstrate possibilities for cultivating greater interest in the multispecies experience of security.

The assumption that animals are conscious and capable of experiencing negative sensations and emotions is at the core of most people's concerns about animal welfare. Investigation of this central assumption should be one goal of animal welfare science. We argue that theory and techniques from cognitive science offer promising ways forward. Evidence for the existence of conscious and non-conscious cognitive processing in humans has inspired scientists to search for comparable processes in animals. In studies of metacognition and blindsight, some species show behaviour that has functional parallels with human conscious cognitive processing. Although unable to definitively answer the question of whether the animals are conscious, these studies provide fresh insights, and some could be adapted for domestic animals. They mark a departure from the search for cognitive complexity as an indicator of consciousness, which is based on questionable assumptions linking the two. Accurate assessment of animal emotion is crucial in animal welfare research, and cognitive science offers novel approaches that address some limitations of current measures. Knowledge of the relationship between cognition and emotion in humans generates a priori frameworks for interpreting traditional physiological and behavioural indicators of animal emotion, and provides new measures (eg cognitive bias) that gauge positive as well as negative emotions. Conditioning paradigms can be used to enable animals to indicate their emotional state through operant responses. Although evidence for animal consciousness and emotion will necessarily be indirect, insights from cognitive science promise further advances in our understanding of this fundamentally important area in animal welfare science.

The dual problem of explaining brain evolution and the way in which it has led to wide species differences in behaviour and physiology has often appeared intractable to scientists. The main limiting factor is that we do not understand enough about how brains work to appreciate why gross or fine morphological differences can lead to the considerable across- as well as within-species differences in behaviour. Even at a molecular level, while two-thirds of our genes are involved in regulating brain function, there is a high degree of homology within different phyla. In the context of quality of life (QoL), arguably the most important consideration is that the brain you have evolved is adapted to the environment you are living in and is capable of generating ‘conscious’ experience. When that environment is radically altered, issues arise regarding whether there is sufficient adaptability to cope and the extent to which mental as well as physical suffering might be experienced as a consequence. At the other end of the spectrum there is the question of how enriched social and physical environments might enhance QoL through promoting positive affect. Here I will discuss potential functional contributions of differences in brain size and organisation and the impact of experience. I will mainly focus on mental functioning and show particularly that capacities for consciousness, emotional experience, social interaction and cognition and behavioural flexibility are likely to be widespread in other animal species, even if less developed than in humans.

Recent scientific findings indicate that consciousness is a fundamental biological adaptation. The known brain correlates of consciousness appear to be phylogenetically ancient, going back at least to early mammals. In all mammals, alertness and sensory consciousness are required for the goal-directed behaviours that make species survival and reproduction possible. In all mammals, the anatomy, neurochemistry and electrical activity of the brain in alert states show striking similarities.

After more than seven decades of cumulative discoveries about waking and sensory consciousness, we have not yet found any fundamental differences between humans and other mammals. Species differences such as the size of neocortex seem to be irrelevant to the existence of alertness and sensory consciousness, though different mammals obviously specialize in different kinds of sensory, cognitive and motor abilities.

Sceptics sometimes claim that objective evidence for consciousness tells us little about subjective experience, such as the experience of conscious pain. Scientifically, however, plausible inferences are routinely based on reliable and consistent patterns of evidence. In other humans, we invariably infer subjective experiences from objective behavioural and brain evidence - if someone yells ‘Ouch!’ after striking a finger with a hammer, we infer that they feel pain. The brain and behavioural evidence for subjective consciousness is essentially identical in humans and other mammals. On the weight of the objective evidence, therefore, subjective experience would seem to be equally plausible in all species with human-like brains and behaviour. Either we deny this experience to other humans (which is rarely done) or, to be consistent, we must also attribute it to other species that meet the same objective standards. It seems that the burden of proof for the absence of subjectivity in mammals should be placed on the sceptics.

Determining objective measures for proof of consciousness in non-human animals has been helped by improved understanding of neural correlates of human consciousness. Functional imaging and neuropsychological studies have shown remarkable overlap between structures involved in actual perception of social and non-social objects and those involved in forming mental images of them. One area of particular interest is individual face recognition. This involves regions of the temporal lobe that are mainly only activated by actual perception or mental imagery of faces. Using behavioural, neuroanatomical and neurophysiological approaches in sheep, we have found that they have similar specialized abilities for recognizing many individuals from their faces. They have developed the same specialized neural processing regions in the temporal lobe for aiding such recognition. Furthermore, parallel activation of other brain regions controlling behavioural and emotional responses only occurs when they are overtly interested in the individuals whose faces they perceive. Such interest might therefore equate to their becoming consciously aware of them. Preliminary experiments have indicated that sheep may form and use mental images and that the regions of the temporal lobe that respond to faces can also do so under conditions where faces are suggested but do not actually appear. Such similarities between humans and sheep in this form of social recognition make it difficult to claim that humans can form mental images of faces whereas sheep cannot. While the ability to form and use mental imagery is not in itself definitive proof of consciousness, it is an important component part.

The level of priority and resource given to the care of organisms is influenced by beliefs and understanding about their capacities for conscious awareness. Variation in attitudes to animal welfare around the world today is partly a reflection of this. Improved understanding of the range of phenomena of which animals may be conscious is likely to lead to greater global consensus about the importance of high standards of animal welfare. This is a matter of current relevance. In the global free market there is a danger that efforts in one country to raise standards for farm or laboratory animals will be compromised by competition from others which employ cheaper, less welfare-friendly systems. Scientific developments which inform us about animals’ capacities for pleasant and unpleasant feelings will play an important role in the development of global agreement about animal welfare standards. Deciding which animals might have the capacity for consciousness, and thus for suffering, and of what they might be conscious, are fundamental issues which set boundaries to the ranges of species to be given basic or special forms of welfare protection. In practice, such lines have to be drawn and it is crucial that they are drawn in the right place. This is a difficult but essential task and society looks to scientists for guidance on the matter. There have been many developments in recent years in scientific approaches to the study of consciousness in animals which are pertinent to this debate.

Awareness of the self and awareness of others are difficult faculties to define. Part of the problem lies in the wide range of abilities that involve various aspects of awareness. Some of the most commonly studied abilities focus on the self-awareness of the individual. These abilities range from the capacity to distinguish self from non-self to the competency to reflect on one's past, present or future condition. Another set of abilities that is relevant to the study of awareness involves the interactions of individuals, and includes behaviours such as deception and empathy. We explore the possibility that species other than humans engage in deception and empathy, and consider the implications of such behaviours for self-awareness and other-awareness in these species. Although examples from a variety of species are provided, many examples come from dolphins and whales. This reflects both the authors’ interest in these animals and the possibility that large-brained creatures are more likely to engage in deliberate deception and/or true empathy.

Thinking about animal consciousness is beset with many pitfalls, a few of which are: i) lack of clarity in words used, especially confusing ‘cognition’ with ‘consciousness’ and using words such as ‘emotion’ in both an objective sense (behaviour and physiology) and to imply consciousness; ii) failing to acknowledge sufficiently that different people use different versions of the argument from analogy with ourselves to infer consciousness in non-humans in animals; iii) assuming that choice and preference imply consciousness; iv) assuming that autonomic responses imply consciousness (a particular danger to those who look for physiological ‘measures’ of animal welfare); v) assuming that complexity of behaviour implies complexity of cognition and in turn consciousness; and vi) assuming that only cognitively complex organisms are conscious. Consciousness raises many questions of direct relevance to animal welfare that as yet have no answers, but finding possible answers may be made slightly easier if we avoid these obvious pitfalls.

The attempt to provide a firm scientific basis for understanding consciousness is now in full swing, with special contributions from two areas. One is experimental: brain imaging is providing ever increasing detail of the brain structures used by humans (and other animals) as they solve a variety of tasks, including those of higher cognition. The other is theoretical: the discipline of neural networks is allowing models of these cognitive processes to be constructed and tested against the available data. In particular, a control framework can be created to give a global view of the brain. The highest cognitive process, that of consciousness, is naturally a target for such experimentation and modelling. This paper reviews available data and related models leading to the central representation, which involves particular brain regions and functional processing. Principles of consciousness, which have great relevance to the question in the title, are thereby deduced. The requisite neuronal systems needed to provide animal experience, and the problem of assessing the quality and quantity of such experience, will then be considered. In conclusion, animal consciousness is seen to exist broadly across those species with the requisite control structures; the level of pain and other sensations depends in an increasingly well-defined manner on the complexity of the cerebral apparatus.

Muslims derive their dietary laws from the Quran (Islamic Holy Book) and other Islamic scriptures. These religious scriptures prohibit them from consuming meat from animals that die before they are bled-out. Some Muslim authorities have interpreted this to mean that, in addition to the animal being alive, it must also be conscious prior to neck-cutting. This has led to a section of the Muslim community rejecting pre-slaughter stunning for halal meat production with the belief that all forms of stunning lead to instantaneous death. It must be noted that some jurists have debunked claims that animals must be conscious before they are bled-out because it does not appear to be mentioned anywhere in the scriptures. This paper reviews literature on the role of the brain in the control of conscious perception and death and considers the different scholarly definitions of death and how they impact the interpretation of halal slaughter rules and the impact on animal welfare.

The aim of this study was to assess brain activity in lambs during slaughter without stunning and its correlation with heart rate (HR) and the absence of physiological reflexes. The index of consciousness (IoC-view®) assesses consciousness by an algorithm that analyses the EEG and gives an index from 0 (unconscious) to 100 (conscious). Eight lambs (Merino breed) of 20 to 25 kg live weight were individually restrained in a stretcher and three skin electrodes were placed at the level of the frontal bone. The electrodes were connected to the IoC-view®. Two additional electrodes were placed on the chest and the HR was transferred to a watch monitor. Recording time started 2 min prior to sticking to attain the basal IoC and HR value of each animal. During bleeding, presence of corneal reflex and rhythmic breathing were recorded every 10 s until brain death. Rhythmic breathing disappeared at an average time of 44 (± 4.2) s after sticking, ranging between 30 and 60 s. The corneal reflex disappeared at 116 (± 11.01) s, ranging between 80 and 160 s after sticking. Changes in the brain activity occurred between 22 to 82 s after sticking (52 [± 20.2] s). In five out of six animals the HR increased (177 [± 22.7] beats min−1) compared to basal values (139 [± 8.4] beats min−1) at 115 (± 97.5) s after sticking. Both brain activity and physiological reflexes revealed that when bleeding is performed, through a transverse incision across the neck without stunning, the onset of unconsciousness could last 1 min which impaired animal welfare. This prolonged consciousness compared to other authors’ findings may be attributable to inefficient bleeding when lambs are slaughtered without head restraint.