This book offers a new theoretical framework within which to understand “the mind-body problem”. The crux of this problem is phenomenal experience, which Thomas Nagel famously described as “what it is like” to be a certain living creature. David Chalmers refers to the problem of “what-it-is-like” as “the hard problem” of consciousness and claims that this problem is so “hard” that investigators have either just ignored the issue completely, investigated a similar (but distinct) problem, or claimed that there is literally (...) nothing to investigate – that phenomenal experience is illusory. This book contends that phenomenal experience is both very real and very important. Two specific “biological naturalist” views are considered in depth. One of these two views, in particular, seems to be free from problems; adopting something along the lines of this view might finally allow us to make sense of the mind-body problem. -/- An essential read for anyone who believes that no satisfactory solution to “the mind-body problem” has yet been discovered. (shrink)
This goal of this thesis in the philosophy of nature is to move us closer towards a true biological science of consciousness in which the evolutionary origin, function, and phylogenetic diversity of consciousness are moved from the field’s periphery of investigations to its very centre. Rather than applying theories of consciousness built top-down on the human case to other animals, I argue that we require an evolutionary bottomup approach that begins with the very origins of subjective experience in order to (...) make sense of the place of mind in nature. To achieve this goal, I introduce and defend the pathological complexity thesis as both a framework for the scientific investigation of consciousness and as a lifemind continuity thesis about the origins and function of consciousness. (shrink)
Which non-human animals are phenomenally conscious? In this paper I argue that the distribution of phenomenal consciousness in the animal world is ultimately an unsolvable issue, because of an underlying problem inherent in the field: what I call the Kinda Hard Problem. The Kinda Hard Problem arises because the grounds on which we base our consciousness attributions to humans third-personally are either unavailable or ambiguous once we move to the animal case. Its nature is that of an epistemic problem: we (...) cannot collect enough evidential grounds to justify attributions of phenomenal consciousness (and attributions of its lack) to non-human animals. Thus, it is impossible to ground rational belief one way or another regarding animal consciousness. This paper presents the problem and explains how it differs from other problems of consciousness. (shrink)
Segundo-Ortin & Calvo argue that plants have a surprisingly varied and complex behavioral repertoire. Which of these behavioral capacities are credible indicators of sentience? If we use the standards of evidence common in discussions of animal sentience, the behavioral capacities reviewed are insufficient evidence of sentience. Even if some putative indicators of animal sentience are present in plants, it is not clear whether what we should conclude is that plants are sentient or that those indicators are inadequate.
Like many others, I see Crump et al. (2022) as a milestone for improving upon previous guidelines and for extending their framework to decapod crustaceans. Their proposal would benefit from a firm evolutionary foundation by adding the comparative measurement of life-history complexity as a ninth criterion for attributing sentience to nonhuman animals.
The science of animal consciousness investigates (i) which animal species are conscious (the distribution question) and (ii) how conscious experience differs in detail between species (the quality question). We propose a framework which clearly distinguishes both questions and tackles both of them. This two-tier account distinguishes consciousness along ten dimensions and suggests cognitive capacities which serve as distinct operationalizations for each dimension. The two-tier account achieves three valuable aims: First, it separates strong and weak indicators of the presence of consciousness. (...) Second, these indicators include not only different specific contents but also differences in the way particular contents are processed (by processes of learning, reasoning or abstraction). Third, evidence of consciousness from each dimension can be combined to derive the distinctive multi-dimensional consciousness profile of various species. Thus, the two-tier account shows how the kind of conscious experience of different species can be systematically compared. (shrink)
In this book, the author investigates if animals have consciousness. Two salient issues covered in it are the nature of subjectivity and how a sense of self (and awareness of the other) evolves from its biological underpinnings.
Os debates sobre a existência da consciência em animais não humanos vêm ganhando cada vez mais destaque nos círculos científicos e filosóficos ao redor do mundo. Um importante empecilho que a área atualmente enfrenta diz respeito à construção de um método confiável capaz de identificar se um determinado animal não humano possui estados mentais conscientes. A literatura nomeia essa questão de “o problema da mensuração da consciência animal”. A presente dissertação possui como objetivo analisar e responder esse problema através da (...) combinação entre o uso de evidências empíricas e de ferramentas filosóficas. Dito isso, existem inúmeras formas de respondê-lo. Ao longo do texto, analisarei algumas das que são consideradas mais relevantes na discussão atual. Uma delas é a concepção cética de que não há questão de fato sobre os animais não humanos serem ou não conscientes. Em contraste, as abordagens neutras e newtonianas buscam se esquivar de compromissos metafísicos e teóricos para atribuir consciência aos animais. Ao final da dissertação defenderei a chamada “abordagem teórica leve”, posição originalmente proposta pelo filósofo Jonathan Birch. Buscarei mostrar que ela é atualmente a hipótese empiricamente mais adequada e filosoficamente plausível dentre as disponíveis na literatura. (shrink)
Which animals have conscious experiences? Many different, diverse and unrelated behaviors and cognitive capacities have been proposed as tests of the presence of consciousness in an animal. It is unclear which of these tests, if any, are valid. To remedy this problem, I develop a list consisting of eight desiderata which can be used to assess putative tests of animal consciousness. These desiderata are based either on detailed analogies between consciousness-linked human behavior and non-human behavior, on theories of consciousness or (...) on methods from human consciousness science. If a test or set of tests satisfies more of these desiderata, passing it provides stronger evidence of consciousness. Moreover, one can design future tests of animal consciousness with the intention of satisfying these desiderata to ensure their evidential strength. (shrink)
Consciousness has an important role in ethics: when a being consciously experiences the frustration or satisfaction of its interests, those interests deserve higher moral priority than those of a behaviourally similar but non-conscious being. I consider the relationship between this ethical role and an a posteriori (or “type-B”) materialist solution to the mind-body problem. It is hard to avoid the conclusion that, if type-B materialism is correct, then the reference of the concept of phenomenal consciousness is radically indeterminate between a (...) neuronal-level property that is distinctive to mammals and a high-level functional property that is much more widely shared. This would leave many non-mammalian animals (such as birds, fish, insects and octopuses) with indeterminate moral status. There are ways to manage this radical moral indeterminacy, but all of these ways lead to profoundly troubling consequences. (shrink)
Crump et al.’s contribution to assessing whether decapods feel pain raises an important question: Is pain distributed unevenly across the order? The case for pain appears stronger in Pleocyemata than in Dendrobranchiata. Some studies report pain avoidance behaviors in Dendrobranchiata (Penaeidae) shrimp, but further studies are needed to determine whether the chemicals used are acting as analgesics to relieve pain, or as soporifics to reduce overall alertness. If the latter, the most farmed shrimp species may not require the same level (...) of protection as crabs, crayfish, and lobsters. (shrink)
In a new study, Ben-Haim et al. use subliminal stimuli to separate conscious and unconscious perception in macaques. A programme of this type, using a range of cognitive tasks, is a promising way to look for conscious perception in more controversial cases.
Philosophical attention to animals can be found in a wide range of texts throughout the history of philosophy, including discussions of animal classification in Aristotle and Ibn Bâjja, of animal rationality in Porphyry, Chrysippus, Aquinas and Kant, of mental continuity and the nature of the mental in Dharmakīrti, Telesio, Conway, Descartes, Cavendish, and Voltaire, of animal self-consciousness in Ibn Sina, of understanding what others think and feel in Zhuangzi, of animal emotion in Śāntarakṣita and Bentham, and of human cultural uniqueness (...) in Xunzi. In recent years, there has been increased attention to animal minds in philosophical discussions across many areas of metaphysics, epistemology, and value theory. Given that nonhuman animals share some biological and psychological features with humans, and that we share community, land, and other resources, consideration of nonhuman animals has much to contribute to our philosophical activities. -/- Contemporary philosophy of animal minds often also engages with the sciences of animal cognition and behavior. The science of comparative cognition is a thriving area of research, complementing the philosophical study in two ways. For one, philosophers of animal cognition can use claims resulting from animal cognition studies as premises in philosophical discussions. For example, Jacob Beck (2012) relies on pigeons’ abilities to compare quantities to argue for nonconceptual content; Sidney Carls-Diamante (forthcoming) appeals to octopus behavior and physiology to defend embodied cognition; Richard Moore (2016a) refers to ape gestural communication to rethink the requirements for intentional communication; Andrew Barron and Colin Klein (2016) appeal to insect cognition research to defend new theories of consciousness; Sarah Vincent, Rebecca Ring, and Kristin Andrews (2019) cite dolphins’ social practices to argue for the existence of norms that do not require metacognition. -/- In addition, philosophers of animal cognition can examine the epistemology and methods used to justify the claims that arise from the science. Research into animal cognition has resulted in surprising claims about animal capacities, such as sociality in garter snakes (Skinner & Miller 2020), tool-use in ants (Maák et al. 2017), mirror self-recognition in fish (Kohda et al. 2019), empathy in rats (Bartal et al. 2011), social learning in fruit flies (Danchin et al. 2018), episodic memory in dogs (Fugazza et al. 2020), addition and subtraction in bees (Howard et al. 2019). How should we evaluate such claims? -/- Some philosophers have argued that animal cognition research is held to a higher standard than human cognition research, and that scientists working with animals are sometimes asked to solve skeptical problems (Halina 2015). Others have challenged scientific assumptions about the relationship between brain size and intelligence, as well as biases against invertebrates (Mikhalevich & Powell 2020). -/- Animal cognition research challenges philosophers to consider that many capacities and behaviors often assumed to require language, sophisticated technological capacities, or legal systems may in fact be had by other animals who lack these properties. In this way, animal cognition research often surprises us by showing that sophisticated-looking activity can be caused through rather simple mechanisms. -/- 1. What is Animal Cognition? 2. Philosophical Assumptions in the Study of Animal Cognition 2.1 Theory-ladenness 2.2 Value-ladenness 2.3 Objectivity 2.4 Simplicity 2.5 Summary 3. Animal Cognition Applied to Philosophy 3.1 The problem of other minds 3.2 The mind-body problem 3.3 Consciousness 3.4 Thought 3.5 Communication 3.6 Social understanding 3.7 The influence of animal cognition on value theory 3.7.1 Ethics 3.7.2 Political theory 3.8 Summary Bibliography Academic Tools Other Internet Resources Related Entries. (shrink)
Descartes held that animals are material automata without minds. However, this raises a puzzle. Descartes’s argument for this doctrine relies on the claims that animals lack language and general intelligence. But these claims seem compatible with the view that animals have minds. As a solution to this puzzle, I defend what I call theintrospective-analogicalinterpretation. According to this interpretation, Descartes employs introspection to show that certain human behaviors do not depend on thought but rather on automatic bodily processes. Descartes then argues (...) that animal behavior resembles only those behaviors that are automatic in humans. Analogy thus supports the view that the behaviors of animals do not depend on thought but are, rather, automatic. And if animal behavior is automatic, then animals are best regarded as automata. (shrink)
Animal welfare is a concept that plays a role within both our moral deliberations and the relevant areas of science. The study of animal welfare has impacts on decisions made by legislators, producers and consumers with regards to housing and treatment of animals. Our ethical deliberations in these domains need to consider our impact on animals, and the study of animal welfare provides the information that allows us to make informed decisions. This thesis focusses on taking a philosophical perspective to (...) answer the question of how we can measure the welfare of animals. Animal welfare science is an applied area of biology, aimed at measuring animal welfare. Although philosophy of animal ethics is common, philosophy focussing on animal welfare science is rare. Despite this lack, there are definitely many ways in which philosophical methods can be used to analyse the methodologies and concepts used in this science. One of the aims of the work in this thesis is to remedy this lack of attention in animal welfare. Animal welfare science is a strong emerging discipline, but there is the need for conceptual and methodological clarity and sophistication in this science if it is to play the relevant informative role for our practical and ethical decision-making. There is thus is a strong role here for philosophical analysis for this purpose. The central aim of this thesis is to provide an account of how we can measure subjective animal welfare, addressing some of the potential problems that may arise in this particular scientific endeavour. The two questions I will be answering are: what is animal welfare, and how do we measure it? Part One of the thesis looks at the subjective concept of animal welfare and its applications. In it, I argue for a subjective welfare view - that animal welfare should be understood as the subjective experience of individuals over their lifetimes - and look at how the subjective welfare concept informs our ethical decision-making in two different cases in applied animal ethics. Part Two of the thesis looks more closely at the scientific role of welfare. Understanding welfare subjectively creates unique measurement problems, due to the necessarily private nature of mental states and here I address a few of these problems, including whether subjective experience is measurable, how we might validate indicators of hidden target variables such as welfare, how we can make welfare comparisons between individual animals and how we might compare or integrate the different types of experience that make up welfare. I end with a discussion of the implications of all these problems and solutions for the practice of welfare science, and indicate useful future directions for research. (shrink)
Birch’s criterion for the precautionary principle imposes a high evidential standard that many cases will fail to meet. Reliable, relevant anecdotal evidence suggestive of animal sentience should also fall within the scope of the precautionary principle. This would minimize potential suffering (as happened in the case of cephalopods) while further evidence is gathered.
Marino & Merskin (2019) demonstrate that sheep are more cognitively complex than typically thought. We should be cautious in interpreting the implications of these results for welfare considerations to avoid perpetuating mistaken beliefs about the moral value of intelligence as opposed to sentience. There are, however, still important ways in which this work can help improve sheeps’ lives.
Mather (2019) has brought together the current empirical research in support of the claim that octopuses possess minds; and the weight of the evidence does appear to support octopus sentience. Being sentient means an organism has welfare concerns, a subjective experience of life that can go well or poorly. Protecting welfare requires knowing what conditions will have a positive or negative impact. Understanding what is in the mind of an octopus will give us valuable insight into what is good for (...) an octopus. (shrink)
Scientists disagree about which capacities a functional analysis of consciousness should target. To address this disagreement, I propose that a good functional analysis should target the etiological functions of consciousness. The trouble is that most hypotheses about the etiological origins of consciousness presuppose particular functional analyses. In recent years, however, a small number of scientists have begun to offer evolutionary hypotheses that are relatively theory neutral. I argue that their hypotheses can serve an independent standard for evaluating among theories of (...) consciousness. (shrink)
If the octopus were conscious, what would its consciousness be like? This paper investigates the structure octopus consciousness, if existent, is likely to exhibit. Presupposing that the configuration of an organism’s consciousness is correlated with that of its nervous system, it is unlikely that the structure of the sort of conscious experience that would arise from the highly decentralized octopus nervous system would bear much resemblance to those of vertebrates. In particular, octopus consciousness may not exhibit unity, which has long (...) been assumed to be the normal or default structure of consciousness. The octopus nervous system is characterized by the following features: its three anatomically distinct components have extensive functional autonomy and little intercommunication; much of the sensory processing and motor control routines—that in vertebrates are localized in the brain—take place within the peripheral arm nervous system; and proprioception and somatotopic representation are significantly downplayed. In this paper, I present the octopus as a highly successful biological organism in which it is plausible that the unified model of consciousness does not hold. (shrink)
In mirror mark tests dolphins twist, posture, and engage in open-mouth and head movements, often repetitive. Because postures and an open mouth are also dolphin social behaviours, we used self-view television as a manipulatable mirror to distinguish between self-examination and social behavior. Two dolphins were exposed to alternating real-time self-view and playback of the same to determine if they distinguished between them. The adult male engaged in elaborate open-mouth behaviors in mirror mode, but usually just watched when playing back the (...) same material. Mirror mode behavior was also compared to interacting with real dolphins. Mark tests were conducted, as well as switches from front to side self-views to see if the dolphins turned. They presented marked areas to self-views to see if the dolphins turned. They presented marked areas to the self-view television and turned. The results suggest self-examination over social behavior. (shrink)
Stanovich & West argue that their observed positive correlations between performance of reasoning tasks and intelligence strengthen the standing of normative rules for determining rationality. I question this argument. Violations of normative rules by cognitively humble creatures in their natural environments are more of a problem for normative rules than for the creatures.
In recent years, explanations of primate cognition highlighted clever arguments, rather than different ability. In the target article, definitions unify, explanations rely on basic nervous system functioning, theory is built on data that fit, and the emphasis is on evolutionary continuities. This commentary describes complexities inherent in the development of empathy that are not accounted for in Preston & de Waal's theory.
Empathy is likely more widely distributed among animals than many researchers realize or perhaps are willing to admit. Studies of social carnivores, other group-living animals, and communication via different modalities will help us learn more about the evolutionary roots and behavioral, sensory, and cognitive underpinnings of empathy, including what it means to have a sense of self. There are also important implications for debates about animal well-being.
The psychological literature about consciousness has been analyzed. It is argued that: 1) Only the higher symbolic cognitive powers like the ability to keep secrets, knowledge of self or self-consciousness, a long-term view on the future, the ability to determine long-term goals, and to freely plan future behavior, add positive fitness-value to consciousness. Without these higher intellectual abilities consciousness will have only negative fitness value and no positive one. The intellectual powers mentioned may therefore be considered as prerequisites for consciousness. (...) Consciousness may therefore only be expected in those animal species that show these capacities in their behavior. So far these capacities have only been described for the anthropoid apes and humans. For the time being, they are therefore the only species in which consciousness may be expected. (shrink)
In this commentary, we raise two issues. First, we argue that in any species, the comparative study of metacognitive abilities must be approached from a developmental perspective and not solely from the adult end state. This makes it possible to explore the trajectories by which different species reach their phenotypic outcome and whether different cognitive systems interact over developmental time. Second, using our research comparing different genetic disorders in humans, we challenge the authors' claim that it is unparsimonious to interpret (...) the same performance in humans and animals in qualitatively different ways, because even the same overt behaviour in different groups of humans can be sustained by different underlying cognitive processes. (shrink)
A-not-B behavior in various mammals and birds suggests it has been selected for during evolution. One scenario is that displacement to B of one food item from a trove at A should not distract the forager. Piagetian stage V experiments may not test for object permanence, but rather for the more abstract notion that physical objects can be unique.
We disagree with two of Rendell and Whitehead's assertions. Culture may be an ancestral characteristic of terrestrial cetacean ancestors; not derived via marine variability, modern cetacean mobility, or any living cetacean social structure. Furthermore, evidence for vocal behavior as culture, social stability, and cognitive ability, is richer in birds than Rendell and Whitehead portray and comparable to that of cetaceans and primates.
We argue that formal analogical reasoning is not a uniquely human trait but is found in chimpanzees, if not in monkeys. We also contest the claim that the relational matching-to-sample task is not exemplary of analogical behavior, and we provide evidence that symbolic-like treatment of relational information can be found in nonhuman species, a point in contention with the relational reinterpretation hypothesis.
The prevailing view that there is significant cognitive continuity between humans and other animals is a result of misinterpretations of the role of evolution, combined with anthropomorphism. This combination has often resulted in an over-interpretation of data from animal experiments. Comparative psychology should do what the name indicates: study the cognitive capacities of different species empirically, without naive evolutionary presuppositions.
This book attempts to advance Donald Griffin's vision of the "final, crowning chapter of the Darwinian revolution" by developing a philosophy for the science of animal consciousness. It advocates a Darwinian bottom-up approach that treats consciousness as a complex, evolved, and multidimensional phenomenon in nature rather than a mysterious all-or-nothing property immune to the tools of science and restricted to a single species. -/- The so-called emergence of a science of consciousness in the 1990s has at best been a science (...) of human consciousness. This book aims to advance a true Darwinian science of consciousness in which its evolutionary origin, function, and phylogenetic diversity are moved from the field’s periphery to its very centre, thus enabling us to integrate consciousness into an evolutionary view of life. Accordingly, this book has two objectives: (i) to argue for the need and possibility of an evolutionary bottom-up approach that addresses the problem of consciousness in terms of the evolutionary origins of a new ecological lifestyle that made consciousness worth having and (ii) to articulate a thesis and beginnings of a theory of the place of consciousness as a complex evolved phenomenon in nature that can help us to answer the question of what it is like to be a bat, an octopus, or a crow. -/- A Philosophy for the Science of Animal Consciousness will appeal to researchers and advanced students interested in advancing our understanding of animal minds as well as anyone with a keen interest in how we can develop a science of animal consciousness. (shrink)
This article surveys philosophical and scientific issues arising from questions about animal consciousness. These questions include: which animals have consciousness and what (if anything) that consciousness might be like. Just what sort(s) of science can bear on these questions is a live issue, but investigations of the behavior and neurophysiology of a wide taxonomic range of animals, as well as the phylogenetic relationships among taxa are relevant. Such questions are also deeply philosophical, with epistemological, metaphysical, and phenomenological dimensions. Progress will (...) ultimately require interdisciplinary work by philosophers willing to engage with the empirical details of animal biology, as well as scientists who are sensitive to the philosophical complexities of the issue. The article discusses motivations for studying animal consciousness, and the common framing of such issues by analogy to the human case. Various concepts of consciousness, their historical background, and the related epistemological and metaphysical issues are described. Theories about the structure and function of consciousness are identified and assessed in the context of ideas about the evolution and distribution of consciousness, and comparative approaches to specific cognitive capacities that have often been taken to indicate that humans are not the only conscious animals. (shrink)
My aim in this paper is to reconstruct Edmund Husserl’s views on the differences between human and animal consciousness, with particular attention to the experience of temporality.In the first section, I situate the topic of animal consciousness in the broader context of Husserl’s philosophy. Whereas this connection has been often neglected, I argue that a phenomenological analysis of non-human subjectivities is not only justified, but also essential to the Husserlian project as a whole.In the second section, I introduce two notions (...) Husserl resorts to when describing the essential difference between human and animal subjectivities, namely “strata of consciousness” and “person.” Drawing on textual evidence, I argue that Husserl does not simply see animals as excluded from the sphere of personhood. Rather, he draws a distinction between two modes of personal life, one of which is said to be unique to human adults.What holds these two modes apart, according to Husserl, is a subject’s relation to time. In the third section, I delve deeper into this topic, asking how we should understand Husserl’s claim that animals live in a “restricted temporality.” I argue that this has less to do with an inability to remember, imagine, or anticipate future events, and more with an inability to explore temporal horizons stretching before one’s birth or after one’s death. By contrast, humans gradually overcome these limitations during ontogeny, thanks to the practice of linguistic communication. This also has consequences for our capacity to engage in genuinely theoretical thought. (shrink)
In a world increasingly concerned with the human species and its future, Marian Stamp Dawkins argues that we need to rethink some of the fundamental questions regarding animal welfare. How are we justified in projecting human emotions on to animals? What kind of mental lives do they have? What can science tell us about their quality of life?
The goal of this programmatic paper is to highlight a close connection between the core problem in the philosophy of medicine, i.e. the concept of health, and the core problem of the philosophy of mind, i.e. the concept of consciousness. I show when we look at these phenomena together, taking the evolutionary perspective of modern state-based behavioural and life-history theory used as the teleonomic tool to Darwinize the agent- and subject-side of organisms, we will be in a better position to (...) make sense of them both as natural phenomena. (shrink)
In order to develop a true biological science of consciousness, we have to remove humans from the center of reference and develop a bottom-up comparative study of animal minds, as Donald Griffin intended with his call for a “cognitive ethology.” In this article, I make use of the pathological complexity thesis (Veit 2022a, b, c ) to show that we can firmly ground a comparative study of animal consciousness by drawing on the resources of state-based behavioral life history theory. By (...) comparing the different life histories of gastropods and arthropods, we will be able to make better sense of the possible origins of consciousness and its function for organisms in their natural environments. (shrink)
Definitions of animal welfare often invoke consciousness or sentience. Marian Stamp Dawkins has argued that to define animal welfare this way is a mistake. In Dawkins’s alternative view, an animal with good welfare is one that is healthy and “has what it wants.” The dispute highlights a source of strain on the concept of animal welfare: consciousness-involving definitions are better able to capture the normative significance of welfare, whereas consciousness-free definitions facilitate the validation of welfare indicators. I reflect on how (...) the field should respond to this strain, ultimately recommending against splitting the concept and in favor of consciousness-involving definitions. (shrink)
Birch’s formulation is persuasive but not nuanced enough to capture at least one situation where it is reasonable to invoke the precautionary principle (PP): when we have multiple, weak, but convergent, lines of evidence that a species is sentient, but no statistically significant evidence of a single credible indicator of sentience within the order as required by BAR. I respond to the worry that if we include such cases in our framework for applying the PP, we open ourselves to the (...) charge of being “unscientific.”. (shrink)
A phenomenal concept is a concept that one possesses only if one has the relevant experience. In this essay, I argue that phenomenal concept theorists, namely, those who believe that we acquire phenomenal concepts through being acquainted with the relevant experience, can never succeed in determining which species of non-human animals are phenomenally conscious because they prohibit any a priori correlation between phenomenal and non-phenomenal concepts. I make my argument by first discussing several ways in which a phenomenal concept theorist (...) may explain which animal species are conscious, namely, with neuro-identity theory, behaviorism, and functionalism, and the problem that these approaches entail. I then illustrate how the alternative approaches of scientific inference to the best explanation, analogical inference, similarity inference, and inference by prototype face the same problem. (shrink)