Thomas Raleigh

Fred Dretske made important contributions to the debate concerning how to distinguish perception from cognition, to the question of whether perceptual content is ‘Rich’ or ‘Sparse’ and to developing the thesis that perceptual experience employs a distinctively iconic format of representation. In Dretske (2015) he offered a method or criterion for determining whether or not two subjects have visual experiences with different phenomenal characters, which he dubbed the ‘Goldilocks Test’. In this paper I criticize Dretske’s proposal, drawing on various visual phenomena in order to argue that this ‘Goldilocks Test’ is not fit for purpose and that it cannot help us to arbitrate the debate between ‘Rich’ and ‘Sparse’ theories of perceptual content.

Deep Neural Networks and other AI systems engineered using advanced machine learning techniques can tackle a wide range of tasks with proficiency that seems to match and even surpass human ability. Yet they are also notoriously opaque, and the worries surrounding their opacity have given rise to the burgeoning field of explainable artificial intelligence, or XAI, with its large variety of explainability methods. This includes post-hoc explainability methods which purport to explain opaque AI systems on the basis of their input-output behaviour alone, without looking into their inner workings. But many authors have expressed deep scepticism about post-hoc explainability. In this paper, we explore the two main objections that the sceptics have raised and argue that we shouldn’t be swayed by them. Using ideas from recent literature on scientific explanation, we draw a parallel between post-hoc explainability methods and idealized models in science and use the parallel in our reply to the sceptics.

While Deep Neural Networks (DNNs) can perform a wide range of tasks at human or greater-than-human level of competence, they are also notoriously opaque. This paper aims to shed light on both the specific nature of this opacity and what it would take to fully or partially remove it. We begin by drawing a clarificatory distinction between two basic dimensions of opacity of complex systems – internal and relational – and explain how various kinds of opacity invoked in recent discussions of DNNs can be understood in terms of these basic dimensions. We then discuss the prospects of removing opacity from DNNs following the methods of two subfields of research in AI – mechanistic interpretability and explainable artificial intelligence (XAI). We finish with a critical discussion of the relevance of what Sullivan (2022a) calls ‘link uncertainty’.

This article discusses two under-explored strands to the concept of ignorance. Firstly, how ignorance relates to a subject’s degrees of belief; secondly how ignorance relates to a subject’s evidence. I also consider a third alleged strand to the concept of ignorance, which is that ignorance requires some kind of normative failure. I argue that this is false; ignorance does not essentially require any such failure. I finish with some reflections on the extent to which conceptual analysis and linguistic intuitions about the English language concept ‘ignorance’ can be relied upon to illuminate the nature of ignorance itself.

Much attention has recently been paid to the idea, which I label ‘External World Acquaintance’ (EWA), that the phenomenal character of perceptual experience is partially constituted by external features. One motivation for EWA which has received relatively little discussion is its alleged ability to help deal with the ‘Explanatory Gap’. I provide a reformulation of this general line of thought, which makes clearer how and when EWA could help to explain the specific phenomenal nature of visual experience. In particular, I argue that by focusing on the different kinds of perceptual actions that are available in the case of visual spatial vs. colour perception, we get a natural explanation for why we should expect the specific nature of colour phenomenology to remain less readily intelligible than the specific nature of visual spatial phenomenology.

A standard form of skeptical scenario, in the tradition of Descartes’ evil demon, raises the prospect that our sensory experiences are deceptive. A less familiar and importantly different kind of skeptical scenario raises the prospect that our beliefs have been debased (Schaffer, 2010). This paper provides a new and improved way of resisting this latter kind of debasing skepticism. Along the way, I explore how the debasing demon scenario connects with some potentially controversial epistemological principles and clear up various neglected or misunderstood points concerning debasing skepticism.

In this chapter we will explore new avenues for developing and defending Naïve Realism (also known as Relationalism), understood as a thesis about the phenomenal character of experience. The core claim of Naive Realism is that ‘what it’s like’ for a subject who enjoys a normal, successful perceptual experience of her surroundings consists in her being directly consciously aware of mind-independent entities in her external environment. It is widely agreed that the strongest challenge to Naïve Realism comes from the alleged possibility of total hallucinations, and the orthodox line of response has been to adopt Disjunctivism about perceptual experience. In this chapter, we will instead focus on an emerging alternative family of responses, which we’ll call ‘New Wave Relationalism’ (NWR). The core commitment of NWR is to reject the initial assumption that there can be total hallucinations that are both non-relational and subjectively indistinguishable from genuine perceptions. The primary aim for this chapter will be to explore and defend this broad NWR strategy for responding to the threat posed by hallucinations to Naïve Realism. We will argue that which specific version or species of NWR a Naïve Realist should adopt will depend on their background methodological and metaphysical commitments.

In the recent epistemological literature much has been written about the nature of suspending judgement or agnosticism. There has also been a surge of recent interest in the nature of ignorance. But what is the relationship between these two epistemically significant states? Prima facie, both suspension and ignorance seem to involve the lack of a correct answer to a question. And, again prima facie, there may be some intuitive attraction to the idea that when one is ignorant whether p, one ought to suspend judgement whether p. In this paper we will explore a range of different possible normative connections between ignorance and suspension of judgement. We will also discuss how both ignorance and suspension are related to having inconclusive evidence. As we will see, the issues can become quite complex due to the fact that there are different, competing views about the nature of ignorance and also about the nature of suspension. Moreover, there are importantly different kinds of epistemic norms. Our overall aim then will be to systematically chart how these different choices will impact the possible normative connections between ignorance and suspension.

I argue that the term ‘naturalism’ is so empty of meaning that it is not suitable for serious theorizing in philosophy. In particular, I argue that the question of whether or not some theory or thesis should count as naturalistic is an empty verbal dispute with no further theoretical significance. I also discuss naturalism construed as a methodological thesis and argue that any plausible version will collapse into triviality. Lastly, I briefly discuss the idea that naturalism is not a thesis at all but rather a ‘stance’ and suggest that this too succumbs to the charge of emptiness. I conclude that we should stop talking about naturalism altogether. [ROYAL INSTITUTE OF PHILOSOPHY 2023 ESSAY PRIZE WINNER.]

The much-discussed ‘Argument from Small Improvement’ has been advanced both as a reason to reject (tripartite) Completeness, one of the standard axioms of decision theory, and to accept the possibility of rationally incomparable choices. But this form of argument cannot be an effective basis for either of these conclusions, unless one already has some prior, independent reason to prefer Transitivity to Completeness as a constraint on rational preferences (or rational values). In particular, I show how a reverse argument from small improvement can be constructed, starting from the assumption of tripartite Completeness, to the conclusion that Transitivity fails. I conclude that this form of argument as it has been standardly presented in the literature is a kind of ‘red herring’. We can only make progress here by evaluating the reasons independent of either such argument to prefer one or other of Transitivity or Completeness.

Sometimes when we describe our own sensory experiences we seem to attribute to experience itself the same sorts of familiar properties – such as shape or colour – as we attribute to everyday physical objects. But how literally should we understand such descriptions? Can there really be phenomenal elements or aspects to an experience which are, for example, quite literally square? This paper examines how these questions connect to a wide range of different commitments and theories about the metaphysics of mind. In particular, I consider whether there may be phenomenological reasons to accept or reject the idea that there are elements or aspects of conscious experience itself which instantiate familiar spatial properties. I also explore how some general theses about the nature of empirical properties can motivate different answers to these questions.

This chapter considers how Liberal Naturalism interacts with the main problems and theories in the philosophy of perception. After briefly summarising the traditional philosophical problems of perception and outlining the standard philosophical theories of perceptual experience, it discusses whether a Liberal Naturalist outlook should incline one towards or away from any of these standard theories. Particular attention is paid to the work of John McDowell and Hilary Putnam, two of the most prominent Liberal Naturalists, whose work was also very influential in the philosophy of perception. There is also a section focusing on colour, an especially important topic not only for debates about perceptual experience but also for debates concerning how our ‘manifest image’ of the natural world relates to our best theories in the physical sciences.

According to Sparse views of perceptual content, the phenomenal character of perceptual experience is exhausted by the experiential presentation of ‘low-level’ properties such as (in the case of vision) shapes, colors, and textures Whereas, according to Rich views of perceptual content, the phenomenal character of perceptual experience can also sometimes involve experiencing ‘high-level’ properties such as natural kinds, artefactual kinds, causal relations, linguistic meanings, and moral properties. An important dialectical tool in the debate between Rich and Sparse theorists is the so-called ‘method of phenomenal contrast’. I explore how this method of phenomenal contrast interacts with the sort of content-externalism made familiar by Putnam. I show that the possibility of Twin Earth style cases places important restrictions on the range of properties that the method of phenomenal contrast could plausibly apply to. Moreover, these restrictions would apply to some paradigmatically low-level properties as well as to some of the frequently advanced high-level properties. I also draw some general lessons about the different ways one might conceive of the relation between phenomenal character and representational content.

Instability occurs when the very fact of choosing one particular possible option rather than another affects the expected values of those possible options. In decision theory: An act is stable iff given that it is actually performed, its expected utility is maximal. When there is no stable choice available, the resulting instability can seem to pose a dilemma of practical rationality. A structurally very similar kind of instability, which occurs in cases of anti-expertise, can likewise seem to create dilemmas of epistemic rationality. One possible line of response to such cases of instability, suggested by both Jeffrey (1983) and Sorensen (1987), is to insist that a rational agent can simply refuse to accept that such instability applies to herself in the first place. According to this line of thought it can be rational for a subject to discount even very strong empirical evidence that the anti-expertise condition obtains. I present a new variety of anti-expertise condition where no particular empirical stage-setting is required, since the subject can deduce a priori that an anti-expertise condition obtains. This kind of anti-expertise case is therefore not amenable to the line of response that Jeffrey and Sorensen recommend.

According to the recent Perceptual Confidence view, perceptual experiences possess not only a representational content, but also a degree of confidence in that content. The motivations for this view are partly phenomenological and partly epistemic. We discuss both the phenomenological and epistemic motivations for the view, and the resulting account of the interface between perceptual experiences and degrees of belief. We conclude that, in their present state of development, orthodox accounts of perceptual experience are still to be favoured over the perceptual confidence view.

According to a certain kind of naïve or folk understanding of physical matter, everyday ‘solid’ objects are composed of a homogeneous, gap-less substance, with sharply defined boundaries, which wholly fills the space they occupy. A further claim is that our perceptual experience of the environment represents or indicates that the objects around us conform to this sort of conception of physical matter. Were this further claim correct, it would mean that the way that the world appears to us in experience conflicts with the deliverances of our best current scientific theories in the following respect: perceptual experience would be intrinsically misleading concerning the structure of physical matter. I argue against this further claim. Experience in itself is not committed to, nor does it provide evidence for, any such conception of the nature of physical matter. The naïve/folk conception of matter in question cannot simply be ‘read-off’ from perceptual appearances.

Barnett provides an interesting new challenge for Dogmatist accounts of perceptual justification. The challenge is that such accounts, by accepting that a perceptual experience can provide a distinctive kind of boost to one’s credences, would lead to a form of diachronic irrationality in cases where one has already learnt in advance that one will have such an experience. I show that this challenge rests on a misleading feature of using the 0–1 interval to express probabilities and show that if we switch to using Odds or Log-Odds, the misleading appearance that there is only ‘a little room’ for one’s credences to increase evaporates. Moreover, there are familiar, independent reasons for taking the Log-Odds scale to provide a clearer picture of the confirmatory effect of evidence. Thus the Dogmatist can after all escape the charge of diachronic irrationality.

A good account of the agnostic attitude of Suspending Judgement should explain how it can be rendered more or less rational/justified according to the state of one's evidence – and one's relation to that evidence. I argue that the attitude of suspending judgement whether p constitutively involves having a belief; roughly, a belief that one cannot yet tell whether or not p. I show that a theory of suspending that treats it as a sui generis attitude, wholly distinct from belief, struggles to account for how suspension of judgement can be rendered more or less rational (or irrational) by one's evidence. I also criticise the related idea that suspension essentially requires an 'Inquiring Attitude'. I show how a belief-based theory, in contrast, neatly accounts for the rational and epistemic features of suspending and so neatly accounts for why an agnostic has a genuine neutral opinion concerning the question whether p, as opposed to simply having no opinion.

This is the introductory essay to the collection of essays: 'Acquaintance: New Essays' (eds. Knowles & Raleigh, forthcoming, OUP). In this essay I provide some historical background to the concept of acquaintance. I examine various Russellian theses about acquaintance that contemporary acquaintance theorists may wish to reject. I consider a number of questions that acquaintance theorists face. I provide a survey of current debates in philosophy where acquaintance has recently been invoked. And I also provide brief summaries of the other essays in this volume.

Bertrand Russell famously distinguished between ‘Knowledge by Acquaintance’ and ‘Knowledge by Description’. For much of the latter half of the Twentieth Century, many philosophers viewed the notion of acquaintance with suspicion, associating it with Russellian ideas that they would wish to reject. However in the past decade or two the concept has undergone a striking revival in mainstream ‘analytic’ philosophy – acquaintance is, it seems, respectable again. This is the first collection of new essays devoted to the topic of acquaintance, featuring contributions from many of the world’s leading experts in this area. The volume showcases the great variety of topics in philosophy of mind, epistemology and philosophy of language for which philosophers are currently employing the concept of acquaintance. This book features an extensive introduction by one of the editors, which provides some historical background as well as summarizing the main debates and issues in contemporary philosophy where appeals to acquaintance are currently being made. The remaining thirteen essays are grouped thematically into the following four sections: (1) Phenomenal Consciousness, (2) Perceptual Experience, (3) Reference, (4) Epistemology.

Much attention has recently been paid to the idea, which I label ‘External World Acquaintance’ (EWA), that the phenomenal character of perceptual experience is partially constituted by external features. One motivation for EWA which has received relatively little discussion is its alleged ability to help deal with the ‘Explanatory Gap’ (e.g. Fish 2008, 2009, Langsam 2011, Allen 2016). I provide a reformulation of this general line of thought, which makes clearer how and when EWA could help to explain the specific phenomenal nature of visual experience. In particular, I argue that by focusing on the different kinds of perceptual actions that are available in the case of visual spatial vs. colour perception, we get a natural explanation for why we should expect the specific nature of colour phenomenology to remain less readily intelligible than the specific nature of visual spatial phenomenology.

This article provides a survey of Wittgenstein’s remarks in which he discusses various kinds of technology. I argue that throughout his career, his use of technological examples displays a thematic unity: technologies are invoked in order to illustrate a certain mechanical conception of the mind. I trace how his use of such examples evolved as his views on the mind and on meaning changed. I also discuss an important and somewhat radical anti-mechanistic strain in his later thought and suggest that Wittgenstein’s attitude to mechanistic explanations in psychology was ultimately quite ambivalent.

In his book “Seeing Dark Things” (2008), Roy Sorensen provides many wonderfully ingenious arguments for many surprising, counter-intuitive claims. One such claim in particular is that when we a silhouetted object – i.e. an opaque object lit entirely from behind – we literally see its back-side – i.e. we see the full expanse of the surface facing away from us that is blocking the incoming light. Sorensen himself admits that this seems a tough pill to swallow, later characterising it as “the most controversial thesis of the book” (2011, p199). I will argue against Sorensen’s controversial thesis and in favour of what seems to me to be a much more natural and commonsensical alternative: when we see a silhouetted object, what we see is its edge and only its edge – so we do not see its entire back-side.

Enactivist (Embodied, Embedded, etc.) approaches in cognitive science and philosophy of mind are sometimes, though not always, conjoined with an anti-representational commitment. A weaker anti-representational claim is that ascribing representational content to internal/sub-personal processes is not compulsory when giving psychological explanations. A stronger anti-representational claim is that the very idea of ascribing representational content to internal/sub-personal processes is a theoretical confusion. This paper criticises some of the arguments made by Hutto & Myin (2013, 2017) for the stronger anti-representational claim and suggests that the default Enactivist view should be the weaker non-representational position.

I consider the ‘inferentialist’ thesis that whenever a mental state rationally justifies a belief it is in virtue of inferential relations holding between the contents of the two states. I suggest that no good argument has yet been given for the thesis. I focus in particular on Williamson (2000) and Ginsborg (2011) and show that neither provides us with a reason to deny the plausible idea that experience can provide non-inferential justification for belief. I finish by pointing out some theoretical costs and tensions associated with endorsing inferentialism.

I consider a new, non-disjunctive strategy for ‘relational’ or ‘naïve realist’ theories to respond to arguments from ‘perfect’ (causally matching) hallucinations. The strategy, in a nutshell, is to treat such hypothetical cases as instances of perception rather than hallucination. After clarifying the form and dialectic of such arguments, I consider three objections to the strategy. I provide answers to the first two objections but concede that the third — based on the possibility of ‘chaotic’ (uncaused) perfect hallucinations — cannot obviously be dealt with by the proposed strategy. However, such ‘chaotic’ scenarios are also problematic for standard representational accounts of experience. Thus I conclude that perfect hallucinations pose no more of a threat to the relational theory than to its main representational rival.