In this paper we1 assess the potential for research on nonhuman animals to address questions about the phenomenology of painful experiences. Nociception, the basic capacity for sensing noxious stimuli, is widespread in the animal kingdom. Even rel- atively primitive animals such as leeches and sea slugs possess nociceptors, neurons that are functionally specialized for sensing noxious stimuli (Walters 1996). Vertebrate spinal cords play a sophisticated role in processing and modulating nociceptive signals, providing direct control of some motor responses to noxious (...) stimuli, and a basic capacity for Pavlovian and instrumental conditioning (Grau et al. 1990; Grau 2002). Higher brain systems provide additional layers of association, top-down control, and cognition. In humans, at least, these higher brain systems also give rise to the conscious experiences that are characteristic of pain. What can be said about the experiences of other animals who possess nervous systems that are similar but not identical to humans? (shrink)

Which nonhuman animals experience conscious pain?1 This question is central to the debate about animal welfare, as well as being of basic interest to scientists and philosophers of mind. Nociception—the capacity to sense noxious stimuli—is one of the most primitive sensory capacities. Neurons functionally specialized for nociception have been described in invertebrates such as the leech Hirudo medicinalis and the marine snail Aplysia californica (Walters 1996). Is all nociception accompanied by conscious pain, even in relatively primitive animals such as Aplysia, (...) or is it the case, as some philosophers continue to maintain, that conscious experiences are the exclu- sive province of human beings? What philosophical and scientific resources are presently available for assessing claims lying between these extremes? (shrink)

Inter-species variation in colour perception poses a serious problem for the view that colours are mind-independent properties. Given that colour perception varies so drastically across species, which species perceives colours as they really are? In this paper, I argue that all do. Specifically, I argue that members of different species perceive properties that are determinates of different, mutually compatible, determinables. This is an instance of a general selectionist strategy for dealing with cases of perceptual variation. According to selectionist views, objects (...) simultaneously instantiate a plurality of colours, all of them genuinely mind-independent, and subjects select from amongst this plurality which colours they perceive. I contrast selectionist views with relationalist views that deny the mind-independence of colour, and consider some general objections to this strategy. (shrink)

In our dealings with animals at least most of us see them as conscious beings. On the other hand the employment of human categories to animals seems to be problematic. Reflecting on the details of human beliefs, for example, casts serious doubt on whether the cat is able to believe anything at all. These theses try to reflect on methodological issues when investigating animal minds. Developing a theory of animal mentality seems to be a test case of the interdisciplinary research (...) programme in cognitive science. From the philosopher`s perspective the most pressing problem is how to talk about animal minds. Can we just employ the vocabulary of human psychology? If not, exploring animal minds contains the non-trivial task of introducing a terminology that allows to see the distinctness of animal minds and to see its connection to the human case. The treatment of some topic in cognitive science has to reach a reflective equilibrium between our intuitions, a phenomenological approach, philosophical conceptual analysis, various empirical approaches and model building. Reflective equilibrium means in this context that we have to reach a coherent model which incorporates as much of our intuitions concerning animal consciousness and integrates at the same time the findings of the different co-operating sciences. There can be various trade-offs in case of conflict between, say, philosophical definitions of mental terms as to be applied to animals, neurophysiology, our reflected intuitions and ethological model building based on a computational theory of animal minds. The paper gives an example of reflective equilibrium in discussing the case for awareness in vertebrates. It considers the role of evolutionary reasoning. The main focus lays on two examples of comparing our human notions (chosen here are “having concepts” and “belief”) with corresponding abilities in animals, and how an appropriate conceptual apparatus dealing with the abilities of animals could be introduced. (shrink)

Shriver and Allen (this volume, this journal; hereafter S&A) make three unconnected criticisms of my views concerning phenomenal consciousness and the question of animal consciousness. First, they claim that my dispositional higher-order thought theory of consciousness has much greater significance for ethics than I recognize. Second, they claim that, in the course of attempting to motivate that theory, I have presented inadequate criticisms of first-order theories (according to which phenomenal consciousness may well be rampant in the animal world). And third, (...) they claim that my argument that the question of animal consciousness might not matter a great deal for comparative psychology may prove too much, showing that such consciousness is genuinely epiphenomenal in ourselves, and undermining some of my own evolutionary arguments in support of higher-order theories. I shall focus mostly on the second and third criticisms. But I begin with a few remarks about the first. (shrink)

According to higher-order thought accounts of phenomenal consciousness it is unlikely that many non-human animals undergo phenomenally conscious experiences. Many people believe that this result would have deep and far-reaching consequences. More specifically, they believe that the absence of phenomenal consciousness from the rest of the animal kingdom must mark a radical and theoretically significant divide between ourselves and other animals, with important implications for comparative psychology. I shall argue that this belief is mistaken. Since phenomenal consciousness might be almost (...) epiphenomenal in its functioning within human cognition, its absence in animals may signify only relatively trivial differences in cognitive architecture. Our temptation to think otherwise arises partly as a side-effect of imaginative identification with animal experiences, and partly from mistaken beliefs concerning the aspects of common-sense psychology that carry the main explanatory burden, whether applied to humans or to non-human animals. (shrink)

This paper argues that it is possible for suffering to occur in the absence of phenomenal consciousness – in the absence of a certain sort of experiential subjectivity, that is. (Phenomenal consciousness is the property that some mental states possess, when it is like something to undergo them, or when they have subjective feels, or possess qualia.) So even if theories of phenomenal consciousness that would withhold such consciousness from most species of non-human animal are correct, this neednt mean that (...) those animals dont suffer, and arent appropriate objects of sympathy and concern. (shrink)

But perhaps we really don't want to know the answers to these questions. We should not despise the desire to be kept in ignorance--aren't there many facts about yourself and your loved ones that you would wisely choose not to know? Speaking for myself, I am sure that I would go to some lengths to prevent myself from learning all the secrets of those around me--whom they found disgusting, whom they secretly adored, what crimes and follies they had committed, or (...) thought I had committed! Learning all these facts would destroy my composure, cripple my attitude towards those around me. Perhaps learning too much about our animal cousins would have a similarly poisonous effect on our relations with them. But if so, then let's make a frank declaration to that effect and drop the topic, instead of pursuing any further the pathetic course many are now embarked upon. (shrink)

Finally, in four chapters greatly expanded for this edition, Griffin considers the latest scientific research on animal consciousness, pro and con, and...

University of Chicago Press, 2001 Review by Adriano Palma, Ph.D. on Aug 1st 2001 Volume: 5, Number: 31.

The question of whether non-human animals are conscious is of fundamental importance. There are already good reasons to think that many are, based on evolutionary continuity and other considerations. However, the hypothesis is notoriously resistant to direct empirical test. Numerous studies have shown behaviour in animals analogous to consciously-produced human behaviour. Fewer probe whether the same mechanisms are in use. One promising line of evidence about consciousness in other animals derives from experiments on metamemory. A study by Hampton (Proc Natl (...) Acad Sci USA 98(9):5359–5362, 2001) suggests that at least one rhesus macaque can use metamemory to predict whether it would itself succeed on a delayed matching-to-sample task. Since it is not plausible that mere meta-representation requires consciousness, Hampton’s study invites an important question: what kind of metamemory is good evidence for consciousness? This paper argues that if it were found that an animal had a memory trace which allowed it to use information about a past perceptual stimulus to inform a range of different behaviours, that would indeed be good evidence that the animal was conscious. That functional characterisation can be tested by investigating whether successful performance on one metamemory task transfers to a range of new tasks. The paper goes on to argue that thinking about animal consciousness in this way helps in formulating a more precise functional characterisation of the mechanisms of conscious awareness. (shrink)

The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value (...) of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. (shrink)

Welfare biology is the study of living things and their environment with respect to their welfare (defined as net happiness, or enjoyment minus suffering). Despite difficulties of ascertaining and measuring welfare and relevancy to normative issues, welfare biology is a positive science. Evolutionary economics and population dynamics are used to help answer basic questions in welfare biology: Which species are affective sentients capable of welfare? Do they enjoy positive or negative welfare? Can their welfare be dramatically increased? Under plausible axioms, (...) all conscious species are plastic and all plastic species are conscious (and, with a stronger axiom, capable of welfare). More complex niches favour the evolution of more rational species. Evolutionary economics also supports the common-sense view that individual sentients failing to survive to mate suffer negative welfare. A kind of God-made (or evolution-created) fairness between species is also unexpectedly found. The contrast between growth maximization (as may be favoured by natural selection), average welfare, and total welfare maximization is discussed. It is shown that welfare could be increased without even sacrificing numbers (at equilibrium). Since the long-term reduction in animal suffering depends on scientific advances, strict restrictions on animal experimentation may be counter-productive to animal welfare. (shrink)

In a series of works, Peter Carruthers has argued for the denial of the title proposition. Here, I defend that proposition by offering direct support drawn from relevant sciences and by undercutting Carruthers argument. In doing the latter, I distinguish an intrinsic theory of consciousness from Carruthers relational theory of consciousness. This relational theory has two readings, one of which makes essential appeal to evolutionary theory. I argue that neither reading offers a successful view.

The standard behavioral index for human consciousness is the ability to report events with accuracy. While this method is routinely used for scientific and medical applications in humans, it is not easy to generalize to other species. Brain evidence may lend itself more easily to comparative testing. Human consciousness involves widespread, relatively fast low-amplitude interactions in the thalamocortical core of the brain, driven by current tasks and conditions. These features have also been found in other mammals, which suggests that consciousness (...) is a major biological adaptation in mammals. We suggest more than a dozen additional properties of human consciousness that may be used to test comparative predictions. Such homologies are necessarily more remote in non-mammals, which do not share the thalamocortical complex. However, as we learn more we may be able to make “deeper” predictions that apply to some birds, reptiles, large-brained invertebrates, and perhaps other species. (shrink)

The question of whether non-human animals are conscious is of fundamental importance. There are already good reasons to think that many are, based on evolutionary continuity and other considerations. However, the hypothesis is notoriously resistant to direct empirical test. Numerous studies have shown behaviour in animals analogous to consciously-produced human behaviour. Fewer probe whether the same mechanisms are in use. One promising line of evidence about consciousness in other animals derives from experiments on metamemory. A study by Hampton (Proc Natl (...) Acad Sci USA 98(9):5359–5362, 2001 ) suggests that at least one rhesus macaque can use metamemory to predict whether it would itself succeed on a delayed matching-to-sample task. Since it is not plausible that mere meta-representation requires consciousness, Hampton’s study invites an important question: what kind of metamemory is good evidence for consciousness? This paper argues that if it were found that an animal had a memory trace which allowed it to use information about a past perceptual stimulus to inform a range of different behaviours, that would indeed be good evidence that the animal was conscious. That functional characterisation can be tested by investigating whether successful performance on one metamemory task transfers to a range of new tasks. The paper goes on to argue that thinking about animal consciousness in this way helps in formulating a more precise functional characterisation of the mechanisms of conscious awareness. (shrink)

Many traditional attempts to show that nonhuman animals are deserving of moral consideration have taken the form of an argument by analogy. However, arguments of this kind have had notable weaknesses and, in particular, have not been able to convince two kinds of skeptics. One of the most important weaknesses of these arguments is that they fail to provide theoretical justifications for why particular physiological similarities should be considered relevant. This paper examines recent empirical research on pain and, in particular, (...) explores the implications of the dissociation between the sensory and the affective pain pathways. It is argued that these results show that the belief that nonhuman animals experience pain in a morally relevant way is reasonable, though not certain. It is further argued that the proposal to explore the relationship between consciousness and various forms of learning challenges the aforementioned skeptics to provide more physiological details for their claims that nonhuman mammals are probably not conscious. (shrink)

Peter Carruthers argues that phenomenal consciousness might not matter very much either for the purpose of determining which nonhuman animals are appropriate objects of moral sympathy, or for the purpose of explaining for the similarities in behavior of humans and nonhumans. Carruthers bases these claims on his version of a dispositionalist higher-order thought (DHOT) theory of consciousness which allows that much of human behavior is the result of first-order beliefs that need not be conscious, and that prima facie judgments about (...) the importance of consciousness are due to confabulation. We argue briefly against his claim that 'the moral landscape can remain unchanged' even if all or nearly all nonhuman animals are taken to be incapable of conscious experience. We then show how a first-order representational (FOR) theory of consciousness might be defended against Carruthers' criticisms. Finally, we argue that Carruthers' appeal to confabulation undercuts his own arguments for an evolutionary explanation for consciousness, posing a greater epiphenomenalist threat to his DHOT theory than he concedes. (shrink)