Multidimensional adjectives are ubiquitous in natural language. An adjective F is multidimensional just in case whether F applies to an object or pair of objects depends on how those objects stand with respect to multiple underlying dimensions of F-ness. Developing a semantics for multidimensional adjectives requires us to address the problem of dimensional aggregation: how do the application conditions of an adjective F in its positive and comparative forms depend on its underlying dimensions? Here we develop a semantics for multidimensional (...) adjectives that incorporates aggregation functions. We then explore an analogy between dimensional aggregation and preference aggregation, bringing results from social choice theory to bear on the number and kind of aggregation functions that are admissible in a context. These results suggest that, for any given adjective, there will often be multiple aggregation functions admissible, meaning that multidimensional comparatives are often vague. (shrink)

The idea that qualities can be had partly or to an intermediate degree is controversial among contemporary metaphysicians, but also has a considerable pedigree among philosophers and scientists. In this paper, we first aim to show that metaphysical sense can be made of this idea by proposing a partial taxonomy of metaphysical accounts of graded qualities, focusing on three particular approaches: one which explicates having a quality to a degree in terms of having a property with an in-built degree, another (...) based on the idea that instantiation admits of degrees, and a third which derives the degree to which a quality is had from the aspects of multi-dimensional properties. Our second aim is to demonstrate that the choice between these accounts can make a substantial metaphysical difference. To make this point, we rely on two case studies (involving quantum observables and values) in which we apply the accounts in order to model apparent cases of metaphysical gradedness. (shrink)

Do factive mental states come in degrees? If so, what is their underlying structure, and what is their theoretical significance? Many have observed that ‘knows that’ is not a gradable verb and have taken this to be strong evidence that propositional knowledge does not come in degrees. This paper demonstrates that the adjective ‘aware that’ passes all the standard tests of gradability, and thus strongly motivates the idea that it refers to a factive mental state that comes in degrees. We (...) will explore a range of structural questions that have been overlooked in regard to our awareness of facts, showing that the degreed structure of awareness has significant implications for our understanding of knowledge. (shrink)

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)

Which systems/organisms are conscious? New tests for consciousness (‘C-tests’) are urgently needed. There is persisting uncertainty about when consciousness arises in human development, when it is lost due to neurological disorders and brain injury, and how it is distributed in nonhuman species. This need is amplified by recent and rapid developments in artificial intelligence (AI), neural organoids, and xenobot technology. Although a number of C-tests have been proposed in recent years, most are of limited use, and currently we have no (...) C-tests for many of the populations for which they are most critical. Here, we identify challenges facing any attempt to develop C-tests, propose a multidimensional classification of such tests, and identify strategies that might be used to validate them. (shrink)

Our pains can be more or less intense, our mental imagery can be more or less vivid, our perceptual experiences can be more or less striking. These degrees of intensity of conscious experiences are all manifestations of a phenomenal property I call mental strength. In this article, I argue that mental strength is a domain-general phenomenal magnitude; in other words, it is a phenomenal quantity shared by all conscious experiences that explains their degree of felt intensity. Mental strength has been (...) largely overlooked in favor of mental states’ type, representational contents, domain-specific phenomenology, or processes such as attention. Considering mental strength in our reflections about the mind illuminates debates about the relation of representational contents and phenomenal character, and it also helps address questions about the structure and functions of consciousness. Mental strength provides a unifying construct to model what is shared in the phenomenology of different types of conscious experiences. (shrink)

In recent years, the science and the philosophy of consciousness has seen growing interest in structural questions about consciousness. This is the Editorial Introduction for a special volume for Philosophy and the Mind Sciences on “Structuralism in Consciousness Studies.”.

To be conscious—according to a common metaphor—is for the “lights to be on inside.” Is this a good metaphor? I argue that the metaphor elicits useful intuitions while staying neutral on controversial philosophical questions. But I also argue that there are two ways of interpreting the metaphor. Is consciousness the inner light itself? Or is consciousness the illuminated room? Call the first sense subjectivity (where ‘consciousness’ =def what makes an entity feel some way at all), and the second sense phenomenal (...) character (where ‘consciousness’ =def what it feels like to be an entity). I use this distinction—as well as the metaphor of the inner light—to clarify some philosophical questions about whether consciousness comes in degrees, whether consciousness is multidimensional, and whether there are borderline cases of consciousness. (shrink)

This article provides a detailed overview of the neuroscience of consciousness.

Under what conditions are material objects, such as particles, parts of a whole object? This is the composition question and is a longstanding open question in philosophy. Existing attempts to specify a non-trivial restriction on composition tend to be vague and face serious counterexamples. Consequently, two extreme answers have become mainstream: composition (the forming of a whole by its parts) happens under no or all conditions. In this paper, we provide a self-contained introduction to the integrated information theory of consciousness (...) (IIT). We show that IIT specifies a non-trivial restriction on composition: composition happens when integrated information is maximized. We compare the IIT-restriction to existing proposals and argue that the IIT-restriction has significant advantages, especially in response to the problems of vagueness and counterexamples. An appendix provides an introduction to calculating parts and wholes with a simple system. (shrink)

What is consciousness and why is it so philosophically and scientifically puzzling? For many years philosophers approached this question assuming a standard physicalist framework on which consciousness can be explained by contemporary physics, biology, neuroscience, and cognitive science. This book is a debate between two philosophers who are united in their rejection of this kind of "standard" physicalism - but who differ sharply in what lesson to draw from this. Amy Kind defends dualism 2.0, a thoroughly modern version of dualism (...) (the theory that there are two fundamentally different kinds of things in the world: those that are physical and those that are mental) decoupled from any religious or non-scientific connotations. Daniel Stoljar defends non-standard physicalism, a kind of physicalism different from both the standard version and dualism 2.0. The book presents a cutting-edge assessment of the philosophy of consciousness and provides a glimpse at what the future study of this area might bring. (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)

One of the most challenging positions in contemporary philosophy of animal consciousness is that proposed by Peter Carruthers (2018a, 2018b, 2019, 2020). According to Carruthers, there is no fact of the matter about whether animals instantiate conscious states. This radical conclusion arises from the conjunction of two theses he endorses: the global workspace theory and the phenomenal concept strategy. This paper argues against Carruthers’ radical viewpoint. Its structure is as follows. First, I will present Carruthers’ theses on consciousness, such as (...) the all-or-nothing characterization of consciousness and the distinction between ‘qualia realism’ and ‘qualia irrealism’. Subsequently, I will provide a brief overview of the global workspace theory and the phenomenal concept strategy. Next, I will reconstruct the arguments that underpin Carruthers’ skepticism about attributing consciousness to animals. Finally, I will present two arguments that challenge Carruthers’ position, highlighting inherent contradictions within his project. Contrary to Carruthers’ controversial assertion (2020, p. 18), I will conclude that animal consciousness deserves attention from both philosophy and the cognitive sciences. (shrink)

Frustration has been growing with mainstay epistemological methods of logical deduction and experimental falsification for assessing theories of consciousness. This paper explores one among several alternatives being proposed: the listed requirements epistemology. A literature search identifies five papers that explicitly list requirements for assessing consciousness theories. These five lists are analysed as a promising starting point, but as yet insufficiently comprehensive to do the method justice. The longest list has 11 items, but 19 unique items are identified across the five (...) lists and a taxonomic analysis by category further surfaces at least 30 potential candidates. Four limitations of the method are discussed, arguing that it is best treated as one practical tool as part of a broader strategy for rigorously assessing consciousness theories and identifying avenues for future research. The conclusion describes a workplan for a sufficiently complete working taxonomy to support the field’s collective endeavours. (shrink)

Dignity often serves as the cornerstone for a justification of rights. However, it has been criticised for its exclusion of nonhuman animals and many human individuals: dignity is traditionally grounded in a capacity that some but not all humans and animals possess, e.g. rationality. To successfully overcome this problem of exclusion, this article argues that we should adopt an account of sentient dignity, i.e. an account of dignity based on sentience alone. The article thus makes three contributions. First, it demonstrates (...) that the basis of dignity has yet to receive a plausible justification. To illustrate this, it outlines the problem of exclusion, and it exposes three problems with a prominent solution offered by Pablo Gilabert. According to Gilabert's view, dignity should be based on several valuable capacities including rationality, sentience and cooperation, among others. However, basing dignity on several capacities (i) risks over-inflating the scope of dignity, (ii) struggles to account for internal complexity, and (iii) produces problematic moral distinctions. Second, the article argues that sentient dignity overcomes these three problems whilst being plausibly inclusive. Finally, it contends that an account of sentient dignity vindicates the non-redundancy of dignity, renders sociopolitical discourse philosophically coherent, and harnesses dignity's potential strategic value. (shrink)

Understanding the biological basis of consciousness is one of the central challenges for modern science. Is a mature scientific explanation really possible, and if so, how should consciousness science be organized so as to achieve this? This thesis is a collection of four papers which approach these questions via an account of the natural categories or ‘kinds’, drawn from philosophy of science, to which paradigmatic mental phenomena like consciousness belong. The central claims defended in the thesis are twofold. Firstly, that (...) to facilitate a mature science of consciousness it is crucial to explicitly introduce a new organizing concept of consciousness modelled on the kinds of concepts which underpin previous successful explanations of other natural phenomena – that of a natural kind concept of consciousness. This draws on the general observation that some concepts are better suited to scientific theorizing about the world than others, and thus that progress in scientific and philosophical domains can be (and indeed, has often been) made by working to refine our existing conceptual schemes to reflect this. Secondly, that a mature science of consciousness will be one which recognizes the reality and explanatory importance of a particular category of mental phenomena called ‘global states of consciousness’ which includes dreaming and wakefulness. Examination of this latter claim leads to a third idea explored and motivated in the thesis which brings consciousness science into closer connection with psychiatry. This is the hypothesis that Major Depressive Disorder involves a change to a subject’s global state of consciousness, marking a change from a state of ordinary wakeful consciousness to an altered ‘depressive state’ of consciousness akin to a dream or psychedelic state. (shrink)

In consciousness science, several promising approaches have been developed for how to represent conscious experience in terms of mathematical spaces and structures. What is missing, however, is an explicit definition of what a 'mathematical structure of conscious experience' is. Here, we propose such a definition. This definition provides a link between the abstract formal entities of mathematics and the concreta of conscious experience; it complements recent approaches that study quality spaces, qualia spaces or phenomenal spaces; it provides a general method (...) to identify and investigate structures of conscious experience; and it may serve as a framework to unify the various approaches from different fields. We hope that ultimately this work provides a basis for developing a common formal language to study consciousness. (shrink)

Dignity is traditionally thought to apply to almost all and almost only humans. However, I argue that an account of a distinctly human dignity cannot achieve a coherent and non-arbitrary justification; either it must exclude some humans or include some nonhumans. This conclusion is not as worrying as might be first thought. Rather than attempting to vindicate human dignity, dignity should extend beyond the human, to include a range of nonhuman animals. Not only can we develop a widely inclusive account (...) of dignity by pursuing this route, but we can still defend the three core principles that lie at the heart of contemporary thinking about dignity: that bearers of dignity possess dignity to an equal degree, in virtue of possessing the same intrinsic worth, and that this generates direct and claimable rights. I thus develop an account of dignity that includes nonhuman animals. I argue that the capacity to value most plausibly grounds dignity. This capacity arises from valenced sentience: a being values insofar as they have experiences that matter to them. I then characterise what follows from this. First, I contend that it is only the capacity to value grounds dignity because this produces the most plausible, simplest, and most explanatorily powerful account of dignity. We ought to reject pluralist accounts which assert a sharp distinction between bearers and non-bearers of rational agency, and biocentric accounts which include non-sentient organic entities. Second, I argue this property grounds an account of dignity that is non-hierarchical. There are no degrees of dignity. Instead, all possessors of the capacity to value have the same kind of intrinsic value, and the same equal fundamental right: to consideration of their interest in leading a life of value. Finally, I argue that since the fundamental right is to consideration, moral agents have claimable duties to engage in a deliberative procedure with actionable requirements. Specific rights are instantiations of this general procedure. Certain revisionist conclusions follow on my view, for instance, that nonhumans should be given greater weight and inclusion in a far wider range of cases, but my account is sensitive to the range of different things different beings value, so it does not generate counterintuitive implications. I conclude that dignity extends beyond the human. (shrink)

The scientific study of consciousness, also referred to as consciousness science, is a young scientific field devoted to understanding how conscious experiences and the brain relate. It comprises a host of theories, experiments, and analyses that aim to investigate the problem of consciousness empirically, theoretically, and conceptually. This thesis addresses some of the questions that arise in these investigations from a formal and mathematical perspective. These questions concern theories of consciousness, experimental paradigms, methodology, and artificial consciousness. -/- Regarding theories of (...) consciousness, the thesis contributes to the understanding of the mathematical structure that some of the formal theories in the field propose. The work presented here targets the theory of consciousness known as Integrated Information Theory (IIT) and the neuroscientific theory known as Predictive Processing Theory or Free Energy Principle in its Active Inference form (AI-PP). The thesis provides axiomatic definitions of the mathematical structures that constitute these theories, and uses these definitions to address some of the open questions surrounding the theories. For AI-PP, this includes a rigorous derivation of the formula for Active Inference via Free Energy minimisation and a proof of compositionality of Free Energy. For IIT, this includes resolutions of some of the criticisms of IIT's formal scope and applications, but also the identification of new issues that concern the formalism and its derivation. When possible, the definitions are provided in the mathematical framework of category theory. -/- Regarding experiments, the thesis addresses the main paradigm for testing and falsifying theories of consciousness currently applied in the field. This paradigm consists of comparing the conscious experience that a theory predicts with the conscious experience that is inferred from behavioural data or report by use of measures of consciousness. The thesis provides a formal model of this paradigm and shows that under a certain condition—if inference and prediction are independent—, any minimally informative theory of consciousness can always be falsified. This is deeply problematic since the field’s reliance on report or behaviour to infer conscious experiences, in conjunction with the general structure of most contemporary theories of consciousness, implies such independence. This observation provides the exact formal underpinning of the well-known unfolding argument. The thesis analyses the origin of the problem and identifies precisely which changes are required to avoid this problem in future research. The thesis furthermore shows that the problem of falsifying theories of consciousness, and of empirical comparisons of theories of consciousness more generally, follows from a pervasive closure paradigm in consciousness science, that consists of taking a neuroscientific account of the brain as input to a theory of consciousness, so as to explain what consciousness is, without allowing for modifications or adaptations of the neuroscientific account that would accommodate consciousness as part of the brain's functioning. As is shown in the thesis, this paradigm has implications that point to a fundamental need of revision. -/- Regarding methodological and conceptual questions, the thesis contributes to the foundations of structural research in consciousness science. Structural research aims to use mathematical structures or mathematical spaces, instead of verbal descriptions or simple categorisations, to represent conscious experiences scientifically, for example when building theories of consciousness, or when exploring new empirical avenues to measure consciousness. Despite considerable advances in this realm, there was, prior to this thesis, no explicit definition of what a mathematical structure of conscious experience should be; that is, how the attribution of mathematical structure to conscious experiences should be systematically understood. Perhaps the most important contribution of this thesis to the field is to propose such a definition. The definition, a structural concept, extends existing approaches wherever available, and provides a basis for developing a common formal language to study consciousness, bridging developments as far apart as psychophysics and phenomenology. In addition, and independently of this proposal, the thesis offers a critical analysis of which metaphysical premises need to be presumed in structural research, whether the use of particular formal tools (such as structure-preserving mappings or homomorphisms) is justified, and how structural theories of consciousness could otherwise be built in the first place. An attempt to expand the results from consciousness to more general problems in philosophy of science is made in the context of the well-known Newman problem. -/- Regarding the question of artificial consciousness—can AI feel?—, the thesis contributes two results that take the form of no-go theorems, as known from physics. The first no-go theorem shows that if consciousness is relevant for the temporal evolution of a system's states—if it is dynamically relevant—, then contemporary AI systems cannot be conscious. That is because AI systems run on CPUs, GPUs, TPUs or other processors which have been designed and verified to adhere to computational dynamics that systematically preclude or suppress deviations. The second no-go theorem is situated in the context of computational functionalism, a view which posits that consciousness is a computation. The theorem shows that if computational functionalism holds true, consciousness cannot be a Turing computation. Rather, it must be a novel type of computation that has recently been proposed by Geoffrey Hinton, called mortal computation. -/- This thesis is part of a global effort to pioneer a mathematical perspective in consciousness science, now called Mathematical Consciousness Science. The hope behind the research carried out in this PhD is to illustrate the power and usefulness of mathematical approaches in different areas of consciousness science, and in doing so, to lay the foundations for future mathematical work that complements and supports empirical and theoretical work in the further development of this exciting field. (shrink)

Does consciousness differ between and within entities? What then makes one conscious experience differ from another? That has been discussed for millennia, yet the more we learn about consciousness the more it seems the differences come from other aspects of our experiences than consciousness itself. Knowing whether consciousness has categories, is degreed or is binary, affects the way we model and look for signs of consciousness and possibly find better treatments for unresponsive patients. This paper (1) examines the two most (...) common views on the variability of consciousness, the multidimensional view and the degreed view, in regards to how consciousness could vary, (2) identifies constricting aspects for both views indicating that the variability of consciousness itself isn’t really argued for in either view, and (3) argues that consciousness is binary by providing a schematic idea of what is needed for being conscious and consciousness. (shrink)