It is arguably the case that olfactory system contains two senses that share the same type of stimuli, sensory transduction mechanism, and processing centers. Yet, orthonasal and retronasal olfaction differ in their types of perceptible objects as individuated by their sensory qualities. What will be explored in this paper is how the account of orthonasal smell developed in the Molecular Structure Theory of smell can be expanded for retronasal olfaction (Young, 2016, 2019a-b, 2020). By considering the object of (...) olfactory perception to be the molecular structure of chemical compounds composing odor plumes, Molecular Structure Theory provides a means for determining an odor’s olfactory quality, how odors can be identified and individuated, and how we perceive smellscapes. Surveying the differences between orthonasal and retronasal olfaction provides the basis for the central argument of the paper that the perceptible objects we refer to as smells and individuated on the basis of their olfactory qualities are only relative to orthonasal olfaction. Retronasal olfaction it is speculatively concluded might play an essential role in our perception of flavorful objects. (shrink)

The dual role of olfaction in both smelling and tasting, i.e. flavour perception, makes it an important test case for philosophical theories of sensory individuation. Indeed, the psychologist Paul Rozin claimed that olfaction is a “dual sense”, leading some scientists and philosophers to propose that we have not one, but two senses of smell: orthonasal and retronasal olfaction. In this paper I consider how best to understand Rozin’s claim, and upon what grounds one might judge there to (...) be one or two distinct olfactory modalities. I conclude that while Rozin may be right that humans have dual occurrences of an olfactory ‘sense’, the concept of a sense-modality, and hence the ‘sense’ of smell, is ambiguous between two different notions: a physiological sensory channel and an experiential modality, along the lines suggested by J. J. Gibson. Furthermore, recognising that these are complementary rather than competing conceptions of a sense-modality enables the formulation of a powerful ‘dual-concept’ framework for posing and addressing questions concerning the complex architecture of human multisensory experience. (shrink)

How much does stimulus input shape perception? The common-sense view is that our perceptions are representations of objects and their features and that the stimulus structures the perceptual object. The problem for this view concerns perceptual biases as responsible for distortions and the subjectivity of perceptual experience. These biases are increasingly studied as constitutive factors of brain processes in recent neuroscience. In neural network models the brain is said to cope with the plethora of sensory information by predicting stimulus regularities (...) on the basis of previous experiences. Drawing on this development, this chapter analyses perceptions as processes. Looking at olfaction as a model system, it argues for the need to abandon a stimulus-centred perspective, where smells are thought of as stable percepts, computationally linked to external objects such as odorous molecules. Perception here is presented as a measure of changing signal ratios in an environment informed by expectancy effects from top-down processes. (shrink)

Is the sense of smell a source of aesthetic perception? Traditional philosophical aesthetics has centered on vision and audition but eliminated smell for its subjective and inherently affective character. This article dismantles the myth that olfaction is an unsophisticated sense. It makes a case for olfactory aesthetics by integrating recent insights in neuroscience with traditional expertise about flavor and fragrance assessment in perfumery and wine tasting. My analysis concerns the importance of observational refinement in aesthetic experience. I argue that (...) the active engagement with stimulus features in perceptual processing shapes the phenomenological content, so much so that the perceptual structure of trained smelling varies significantly from naive smelling. In a second step, I interpret the processes that determine such perceptual refinement in the context of neural decision-making processes, and I end with a positive outlook on how research in neuroscience can be used to benefit philosophical aesthetics. (shrink)

The thesis that smells are objective and independent of perceivers may seem to be in tension with the phenomenon of perceptual variation. In this paper, I argue that there are principled reasons to think that perceptual variation is not a threat to objectivism about smells and is indeed integral to our perceptual relation to the objective world. I first distinguish various kinds of perceptual variation, and argue that the most challenging cases for the objectivist are those where an odourant smells (...) different in different conditions or to different perceivers but the odourant does not change, and there is neither misperception nor a simple failure to perceive a smell. I then argue that there is an independently plausible conception of olfactory experience on which even these challenging cases do not pose a threat to objectivism about smells. Following Kalderon’s work in the domain of colour perception, I argue that olfactory perception provides us with a partial perspective on the smells around us, where this perspective is constrained by the conditions of perception as well as by features of the perceiver. Within this framework, we can allow that perceivers with different sensitivities, or the same perceiver in different conditions, genuinely perceive the same objective smell even though this smell appears different to them. In turn, smells are best understood as qualitatively complex entities, different aspects of which can become perceptually available in different conditions and to different perceivers. (shrink)

There is consensus within the chemosciences that olfactory perception is of the molecular structure of chemical compounds, yet within philosophical theories of smell there is little agreement about the nature of smell. The paper critically assesses the current state of debate regarding smells within philosophy in the hopes of setting it upon firm scientific footing. The theories to be covered are: Naïve Realism, Hedonic Theories, Process Theory, Odor Theories, and non-Objectivist Theories. The aforementioned theories will be evaluated based on their (...) explanations of the (a) the olfactory quality of a smell, (b) smells as distal entities, and (c) our experience of smells as intentional objects. The paper concludes with a defense of Molecular Structure Theory that demonstrating its superiority in accounting for each of these three aspects of smell. (shrink)

Much of the philosophical work on perception has focused on vision. Recently, however, philosophers have begun to correct this ‘tunnel vision’ by considering other modalities. Nevertheless, relatively little has been written about the chemical senses—olfaction and gustation. The focus of this paper is olfaction. In this paper, I consider the question: does human olfactory experience represents objects as thus and so? If we take visual experience as the paradigm of how experience can achieve object representation, we might think (...) that the answer to this question is no. I argue that olfactory experience does indeed represent objects—just not in a way that is easily read from the dominant visual case. (shrink)

Short piece for The Philosophers' Magazine on why philosophers should pay attention to olfaction.

The chapter unfolds in the following sections. The first section exam- ines the reasons for claiming that olfactory perception is spatially unstruc- tured and our experience of smells has an abstract structure. The second section elucidates the further arguments that olfaction cannot generate figure-ground segregation. The third section assesses the conclusion that olfactory perception and experience cannot solve the MPP. Following the overview of the many problems inherent to distal olfactory percep- tion, MST will be introduced as an alternative (...) perspective that allows for figure-ground segregation and perceiving multiple olfactory objects within an array. The chapter then concludes by replying to the shared argument that olfactory distal perception does not have the requisite res- olution to resolve the many properties problem. (shrink)

Smells seem to offer a great opportunity to restructure the reality of the individual. Yet, the olfactory dimension is rarely part of design strategies in architecture, urban planning or landscape urbanism. As designers, we learn to compose mainly with shapes, shapes whose full scale and effects on our senses we will experience only when constructed. However, we should be primarily concerned with creating spaces that not only open the imagination of the individual but also allow positive moods to thrive. In (...) this scheme, all the senses should be called, not just our vision, as is too often the case. The fields of architecture and environmental design must evolve and train professionals capable of conceptualizing both tangible and intangible forms. In this logic, architectural structures offer a way to call upon our own mindscapes; and within the discipline of design a new field of specialization exists: smellscaping. (shrink)

Philosophical discussion about the reality of sensory perceptions has been hijacked by two tendencies. First, talk about perception has been largely centered on vision. Second, the realism question is traditionally approached by attaching objects or material structures to matching contents of sensory perceptions. These tendencies have resulted in an argumentative impasse between realists and anti-realists, discussing the reliability of means by which the supposed causal information transfer from object to perceiver takes place. Concerning the nature of sensory experiences and their (...) capacity to provide access to reality, this article challenges the standard categories through which most arguments in this debate have been framed to date. Drawing on the underexplored case of olfaction, I first show how the details of the perception process determine the modalities of sensory experiences. I specifically examine the role of measurement and analyze its influence on the characterization of perceptions in olfaction. My aim is to argue for an understanding of perception through a process view, rather than one pertaining to objects and properties of objects. (shrink)

We perceive smells as perduring complex entities within a distal array that might be conceived of as smellscapes. However, the philosophical orthodoxy of Odor Theories has been to deny that smells are perceived as having a distal location. Recent challenges have been mounted to Odor Theories’ veracity in handling the timescale of olfactory perception, how it individuates odors as a distal entities, and their claim that olfactory perception is not spatial. The paper does not aim to dispute these criticisms. Rather, (...) what will be shown is that Molecular Structure Theory, a refinement of Odor Theory, can be further developed to handle these challenges. The theory is further refined by focusing on distal perception that requires considering the perceptual object as mereologically complex persisting odor against a background scene conceived of as a smellscape. What will be offered is an expansion of Molecular Structure Theory to account for distal smell perception within natural environments. (shrink)

Olfactory perception provides a promising test case for enactivism, since smelling involves actively sampling our surrounding environment by sniffing. Smelling deploys implicit skillful knowledge of how our movement and the airflow around us yield olfactory experiences. The hybrid nature of olfactory experience makes it an ideal test case for enactivism with its esteem for touch and theoretical roots in vision. Olfaction is like vision in facilitating the perception of distal objects, yet it requires us to breath in and physically (...) contact the sensory object in a manner similar to touch. The paper offers an analysis of the central theoretical components of enactivism, whose soundness and empirical viability are tested using the empirical literature on sniffing. It will be shown that even if sniffing is an essential component of olfaction, the motoric component is not necessary for perceiving smells, which is contrary to the most crucial tenet of enactivism. Thus, the paper concludes that the theory cannot account for olfactory perception. (shrink)

Smell 'sensations' are among the most mysterious of conscious experiences, and have been cited in defense of the thesis that the character of perceptual experience is independent of the physical events that seem to give rise to it. Here we review the scientific literature on olfaction, and we argue that olfaction has a distinctive profile in relation to the other modalities, on four counts: in the physical nature of the stimulus, in the sensorimotor interactions that characterize its use, (...) in the structure of its intramodal distinctions and in the functional role that it plays in people's behaviour. We present two thought experiments in which we detail what would be involved in transforming sounds into smells, and also smells into colours. Through these thought-experiments, we argue that the experiential character of smell derives precisely from the structural features of olfaction, and that an embodied account of olfactory phenomenology is called for. (shrink)

We are immersed within an odorous sea of chemical currents that we parse into individual odors with complex structures. Odors have been posited as determined by the structural relation between the molecules that compose the chemical compounds and their interactions with the receptor site. But, naturally occurring smells are parsed from gaseous odor plumes. To give a comprehensive account of the nature of odors the chemosciences must account for these large distributed entities as well. We offer a focused review of (...) what is known about the perception of odor plumes for olfactory navigation and tracking, which we then connect to what is known about the role odorants play as properties of the plume in determining odor identity with respect to odor quality. We end by motivating our central claim that more research needs to be conducted on the role that odorants play within the odor plume in determining odor identity. (shrink)

Our sense of smell pervasively influences our most common behaviors and daily experience, yet little is known about olfactory consciousness. Over the past decade and a half research in both the fields of Consciousness Studies and Olfaction has blossomed, however, olfactory consciousness has received little to no attention. The olfactory systems unique anatomy, functional organization, sensory processes, and perceptual experiences offers a fecund area for exploring all aspects of consciousness, as well as a external perspective for re-examining the assumptions (...) of contemporary theories of consciousness. It has even been suggested that the olfactory system may represent the minimal neuroanatomy that is required for conscious processing. Here, we seek contributions that should serve as the foundation for future research concerning consciousness using olfaction as a model. -/- Given the variegated nature of research on consciousness, we seek original papers including review articles, original research, and theoretical contributions concerning the nature of olfactory consciousness. The scope of the special edition widely incorporates olfaction as it relates to Consciousness, Awareness, Attention, Phenomenal- or Access-Consciousness, and Qualia. Research concerning olfaction and cross-modal integration as it relates to conscious experience is also welcome. -/- As the initial foray into this uncharted area of research, we welcome contributions from across all disciplines contributing to cognitive neuroscience, including neurobiology, neurology, psychology, philosophy, linguistics, and computer sciences. It is our hope that this special edition will serve as the impetus for future interdisciplinary research on olfaction and consciousness. (shrink)

Amodal completion is the representation of those parts of the perceived object that we get no sensory stimulation from. While amodal completion is rife and plays an essential role in all sense modalities, philosophical discussions of this phenomenon have almost entirely been limited to vision. The aim of this paper is to examine in what sense we can talk about amodal completion in olfaction. We distinguish three different senses of amodal completion – spatial, temporal and feature-based completion – and (...) argue that all three are present and play a significant role in olfaction. (shrink)

Long-standing neglect of the chemical senses in the philosophy of perception is due, mostly, to their being regarded as ‘lower’ senses. Smell, taste, and chemically irritated touch are thought to produce mere bodily sensations. However, empirically informed theories of perception can show how these senses lead to perception of objective properties, and why they cannot be treated as special cases of perception modelled on vision. The senses of taste, touch, and smell also combine to create unified perceptions of flavour. The (...) nature of these multimodal experiences and the character of our awareness of them puts pressure on the traditional idea that each episode of perception goes one or other of the five senses. Thus, the chemical senses, far from being peripheral to the concerns of the philosophy of perception, may hold important clues to the multisensory nature of perception in general. (shrink)

According to Smell Objectivism, the smells we perceive in olfactory experience are objective and independent of perceivers, their experiences, and their perceptual systems. Variations in how things smell to different perceivers or in different contexts raise a challenge to this view. In this paper, I offer an objectivist account of non-illusory contextual variation: cases where the same thing smells different in different contexts of perception and there is no good reason to appeal to misperception. My central example is that of (...) dihydromyrcenol, a substance that can smell both woody and citrusy depending on what other odourants one has recently been exposed to. I first argue that the subjects’ apparently conflicting reports about the way dihydromyrcenol smells are best understood as comparative characterisations of a smell. Given this understanding, different reports can be correctly made in response to perceiving the very same smell. I then argue that the phenomenal difference between the experiences subjects have across contexts can be explained compatibly with Smell Objectivism. On the account proposed, subjects perceive the very same smell but different qualities, notes, or aspects of it are salient to them, depending on the context of perception. I then consider how the proposed defence of Smell Objectivism can be adapted to other cases where the same thing is reported as smelling different in different contexts. (shrink)

Olfaction represents odors, if it represents anything at all. Does olfaction also represent ordinary objects like cheese, fish and coffee-beans? Many think so. This paper argues that it does not. Instead, we should affirm an austere account of the intentional objects of olfaction: olfactory experience is about odors, not objects. Visuocentric thinking about olfaction has tempted some philosophers to say otherwise.

While philosophers of perception develop representational theories of olfactory experiences, there are doubts regarding whether features of olfactory perception can be accommodated within the representationalist framework. In particular, it is argued that the function of olfaction is not to represent stimuli but rather to evaluate it. The paper claims that the major representational accounts of olfaction have problems in accommodating the evaluative aspects of olfactory phenomenology. However, an alternative position, named “olfactory evaluativism,” is proposed which is free of (...) these problems and may serve as a foundation for further developments of representational approach to olfactory experiences. (shrink)

1. Historically, our sense of smell has been deemed informationally impoverished, not very discerning, subjective, ineffable, and generally of little value (for an overview, see e.g., Barwich, 2020...

I sketch and defend an imperativist treatment of the phenomenology associated with disgusting smells. This treatment, I argue, allows us to make better sense than other intentionalist alter-natives both of the neuroanatomy of olfaction, and of a natural pre-theoretical stance regarding the sense of smell.

The sense of smell occupies a peculiar intermediate position within Aristotle's theory of sense perception: odours, like colours and sounds, are perceived at a distance through an external medium of air or water; yet in their nature they are intimately related to flavours, the proper objects of taste, which for Aristotle is a form of touch. In this paper, I examine Aristotle's claims about odour and smell, especially in De Anima II.9 and De Sensu 5, to see what light they (...) shed on his theory of sense perception more generally. In the first half, I argue that neither of the two most influential recent ways of understanding Aristotle's theory of perception can adequately account for what he says about the sense of smell. In the second half, I offer my own positive account, considering and resolving various puzzles raised by Aristotle's claims about the nature of odour and its relation to flavour. Finally, I conclude that Aristotle's discussions of odour and smell suggest a plausible and interesting way of understanding the relationship, on his view, between ordinary, material changes in the sense organs and the activation of the capacity to perceive, considered merely as such. (shrink)

Smells are often said to be ineffable, and linguistic research shows that languages like English lack a dedicated olfactory lexicon. Starting from this evidence, I propose an account of how we talk about smells in English. Our reports about the way things smell are comparative: When we say that something smells burnt or like roses, we characterise the thing's smell by noting its similarity to the characteristic smells of certain odorous things (burnt things, roses). The account explains both the strengths (...) and limitations of our smell discourse, and has implications for philosophical discussions of the relation between language and appearances. (shrink)

Clare Batty has recently argued that the content of human olfactory experience is 'a very weak kind of abstract, or existentially quantified content', and so that 'there is no way things smell'. Her arguments are based on two claims. Firstly, that there is no intuitive distinction between olfactory hallucination and olfactory illusion. Secondly, that olfaction 'does not present smell at particular locations', and 'seems disengaged from any particular object'. The present article shows both of these claims to be false. (...) It shows that naïve subjects find it quite natural to draw a distinction between olfactory hallucination and olfactory illusion. And it argues that the phenomenology of normal olfactory experience is of particular objects as having smells. Two confusions are responsible for Batty thinking otherwise: (1) Batty's examples are cases of extreme pungency, and she mistakes a peculiarity of intense perceptions for a property of olfaction more generally; (2) Batty focuses on very short time slices and so confuses limitations on the information carried by a single sniff for a limitation on the logical form of all olfactory content. (shrink)

According to a common opinion, human olfactory experiences are significantly different from human visual experiences. For instance, olfaction seems to have only rudimentary abilities to represent space; it is not clear whether olfactory experiences have any mereological structure; and while vision presents the world in terms of objects, it is a matter of debate whether there are olfactory object-representations. This paper argues that despite these differences visual and olfactory experiences share a hierarchical subject/property structure. Within this structure, olfactorily experienced (...) odours and visual objects have the same status: they are primary subjects which unify other represented elements into perceptual units. (shrink)

A preview of my book *Perception*. Discusses the relationship between perception and the physical world and the issue of whether reality is as it appears. Useful examples are included throughout the book to illustrate the puzzles of perception, including hallucinations, illusions, the laws of appearance, blindsight, and neuroscientific explanations of our experience of pain, smell and color. The book covers both traditional philosophical arguments and more recent empirical arguments deriving from research in psychophysics and neuroscience. The addition of chapter summaries, (...) suggestions for further reading and a glossary of terms make Perception essential reading for anyone studying the topic in detail, as well as for students of philosophy of mind, philosophy of psychology and metaphysics. (shrink)

It will be obvious to anyone with a slight knowledge of twentieth-century analytic philosophy that one of the central themes of this kind of philosophy is the nature of perception: the awareness of the world through the five senses of sight, touch, smell, taste, and hearing. Yet it can seem puzzling, from our twenty-first-century perspective, why there is a distinctively philosophical problem of perception at all. For when philosophers ask ‘what is the nature of perception?’, the question can be confused (...) with other, purely empirical, questions. For example: how do our sense-organs actually work? What are the mechanisms of smell and taste? How do vision and touch actually provide us with information about the world around us? There is much general agreement, in its broad outlines, about how to answer such questions empirically; but it is not clear what role, if any, philosophy has to play in answering these empirical questions. So if these were the only questions about the nature of perception, then it would not be clear exactly what the philosophy of perception is supposed to be about. (shrink)

We can perceive shapes visually and tactilely, and the information we gain about shapes through both sensory modalities is integrated smoothly into and functions in the same way in our behavior independently of whether we gain it by sight or touch. There seems to be no reason in principle we couldn't perceive shapes through other sensory modalities as well, although as a matter of fact we do not. While we can identify shapes through other sensory modalities—e.g., I may know by (...) smell (the scent of mango) that the object causing my sensory experience is round—this is not perceiving an object as shaped, but rather inferring from the character of one's sensory experience and collateral information that an object of a certain shape caused it. That it is possible to perceive shape by other modalities, however, is suggested by the case of bats and aquatic mammals like dolphins which navigate through their environment by a form of sonar. It is plausible that they have some form of auditory representation of space, and so of shape. These facts about shape perception raise important questions about the relation between those features of perceptual experience which are intrinsic to different sensory modalities and the nature of our perceptual representation of shapes, and, more generally, of the space within which we perceive shaped objects to be located. John Campbell's paper, "Molyneux's Problem" (see above), raises a number of interesting and important questions about the nature of our perception of shape properties, particularly the cross-modal nature of shape perception, and ties them to more general questions about the nature both of perceptual.. (shrink)

Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of (...) perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception. (shrink)

This paper shows that direct-object perceptual verbs, such as "hear", "smell", "taste", "feel", and "see", share a collection of distinctive semantic behaviors with depictive verbs, among which are "draw'', "paint", "sketch", and "sculpt". What explains these behaviors in the case of depictives is that they are causative verbs, and have lexical decompositions that involve the creation of concrete artistic artifacts, such as pictures, paintings, and sculptures. For instance, "draw a dog" means "draw a picture of a dog", where the latter (...) occurrence of "draw" denotes a creative activity. While perceptual verbs are not obviously causatives, they have analogous decompositions involving noun phrases that denote modality-specific sense-objects, such as a sounds, smells, flavors, touches, and sights. Thus, "hear a trumpet" means "hear the sound of a trumpet", and the same holds, mutatis mutandis, for verbs denoting the other sensory modes. If we take this analogy at face value, our perceptual reports will commit us to a form of the sense-datum theory of perception. While the analogy can be resisted, resistance requires taking on unexpected commitments. (shrink)

Our emotional states affect how we perceive the world. If I am stressed, annoyed, or irritated, I might experience the sound of children laughing and screaming as they play around the house in a negative manner — it is unpleasant, loud, piercing, and so on. Yet, if I’m in a relaxed, happy, loving mood, the very same sounds might be experienced as pleasant, playful, warm, and so on. The sounds being made by the children are the same in both cases, (...) but how they are experienced differs. The auditory experience is affected by the emotional state that I am in. I perceive the sounds differently depending on how I’m feeling. Although this might at first seem to be a trivial observation, it certainly is not. We take for granted that our perceptual experiences give rise to justified beliefs and knowledge. Thus, if my perceptual experience of an object can differ based on my emotional state, and I take my perceptual experience to justify my beliefs and even lead to knowledge, then we might have a problem. If emotions — which are not fixed and in large part uncontrolled — affect our ability to accurately perceive the world, then they may undermine the justified beliefs and knowledge gained on the basis of our perceptual experience of the world. My goal here is to explore this potential problem. -/- I consider how we might understand the effect that emotions have on the justification of our perceptual beliefs about the world, beliefs that we acquire from a variety of sensory modalities — audition, gustation olfaction, and so on. I take the problem to be associated with one of two forms of perceptual influence: penetration or multisensory integration. In any given perceptual moment there are multiple sensory modalities and mental states at play, each affecting the overall experience. Whether we understand the influence of emotion on perception as a form of non-perceptual penetration or a form of non-visual sensory perception of the inner body — interoception — the potential epistemological difficulties remain: how can we be said to acquire justified beliefs and knowledge on the basis of such influenced perceptual experience. As has been the norm, only the five exteroceptive senses of vision, audition, olfaction, taste and touch are typically discussed in the context of sensory perception. However, as I argue, there is strong reason to accept the claim that emotional experience is a form of interoception, and that interoception ought to be considered when discussing sensory perception. In this way, then, I propose that clarifying the role played by interoception in sense perception across modalities is necessary if we are to make progress on the epistemological problems at hand. (shrink)

Many philosophers believe that there is a causal condition on perception, and that this condition is a conceptual truth about perception. A highly influential argument for this claim is based on intuitive responses to Gricean-style thought experiments. Do the folk share the intuitions of philosophers? Roberts et al. (2016) presented participants with two kinds of cases: Blocker cases (similar to Grice’s case involving a mirror and a pillar) and Non-Blocker cases (similar to Grice’s case involving a clock and brain stimulation). (...) They found that a substantial minority agreed that seeing occurs in the Non-Blocker cases, and that in the Blocker cases significantly less agreed that seeing occurs. They thus hypothesized that folk intuitions better align with a no blocker condition than with a causal condition. This paper continues this line of enquiry with two new experiments. The paper investigates the generality and robustness of Roberts et al.’s findings by expanding the sense modalities tested from only vision to audition and olfaction as well. The paper also uses Gricean-style thought experiments as a case study for investigating the “reflection defense” against the negative project in experimental philosophy. Our results replicate and extend Roberts et al.’s study and support their hypothesis that folk intuitions better align with a no blocker condition. They also provide an empirical reason to doubt the reflection defense. (shrink)

Higher animals need to identify and track material objects because they depend on interactions with them for nutrition, reproduction, and social interaction. This paper investigates the perception of material objects. It argues, first, that material objects are tagged, in all five external senses, as bearers of the features detected by them. This happens through a perceptual process, here entitled Generalized Completion, which creates the appearance of objects that have properties that transcend the activation of sensory receptors. The paper shows, secondly, (...) that material objects are privileged subjects for perceived motion and interaction. That is, they are perceived as subjects for these properties while their parts seem to be subjects only derivatively. Material objects are the only perceptual subjects that are both multisensory and privileged. (shrink)

Seeing one’s laptop to be missing, hearing silence and smelling fresh air; these are all examples of perceptual experiences of absences. In this paper I discuss an example of absence perception in the tactual sense modality, that of tactually perceiving a tooth to be absent in one’s mouth, following its extraction. Various features of the example challenge two recently-developed theories of absence perception: Farennikova’s memory-perception mismatch theory and Martin and Dockic’s meta-cognitive theory. I speculate that the mechanism underlying the experience (...) is a body schema that has failed to update itself. (shrink)

Much of the philosophical work on perception has focused on vision. Recently, however, philosophers have begun to correct this ‘tunnel vision’ by considering other modalities. Nevertheless, relatively little has been written about the chemical senses—olfaction and gustation. The focus of this paper is olfaction. In light of new physiological and psychophysical research on olfaction, I consider whether olfactory experience is object-based. In particular, I explore the claim that “odor objects” constitute sensory individuals. It isn’t obvious—at least at (...) the outset—whether they meet the widely accepted principles of object individuation and recognition at work in the visual and auditory cases. Among the general issues I consider, then, is whether these traditional principles form necessary, or simply sufficient, conditions on object perception. As we see, at the very least, considering the object-recognition model of olfaction challenges us to look more closely at well-entrenched models of object perception. But the payoff of doing so is high. We not only learn something about a modality that philosophers have historically neglected; by asking new questions and challenging old assumptions, we also further our understanding of perception in general. (shrink)

Although vision is the de facto model system of consciousness research, studying olfactory consciousness has its own advantages, as this collection of articles emphatically demonstrates. One advantage of olfaction is its computational and phenomenological simplicity, which facilitates the identification of basic principles. Other researchers study olfactory consciousness not because of its simplicity, but because of its unique features. Together, olfaction's simplicity and its distinctiveness make it an ideal system for testing theories of consciousness. In this research topic, the (...) results of recent research into olfactory consciousness are presented. (shrink)

The philosophy of perception has been mostly focused on vision, to the detriment of other modalities like audition or olfaction. In this paper I focus on olfaction and olfactory experience, and raise the following questions: is olfaction a perceptual-representational modality? If so, what does it represent? My goal in the paper is, firstly, to provide an affirmative answer to the first question, and secondly, to argue that olfaction represents odors in the form of olfactory objects, to (...) which olfactory qualities are attributed. In order to do this I develop an empirically adequate notion of olfactory object that is sensitive to the peculiarities of olfaction, and defend it against various objections. (shrink)

One of the crucial characteristics of the olfactory modality is that olfactory experiences commonly present odours as pleasant or unpleasant. Indeed, because of the importance of the hedonic aspects of olfactory experience, it has been proposed that the role of olfaction is not to represent the properties of stimuli, but rather to generate a valence-related response. However, despite a growing interest among philosophers in the study of the chemical senses, no dominant theory of sensory pleasure has emerged in the (...) case of human olfaction. The aim of this paper is to develop an argument based on the way in which olfactory valence is neurally encoded; one that demonstrates an advantage of the indicative representational approach to olfactory valence over approaches that characterise valence in terms of desires or commands. The argument shows that it is plausible to understand olfactory valence, at least in part, in terms of indicative representations. (shrink)

Contemporary neuroscientific theories of consciousness are typically based on the study of vision and have neglected olfaction. Several of these (e.g. Global Workspace Theories, the Information Integration theory, and the various theories offered by Crick and Koch) claim that a thalamic relay is necessary for consciousness. Studies on olfaction and the olfactory system's anatomical structure show this claim to be incorrect, thus showing these theories to be either false or inadequate as general and comprehensive accounts of consciousness. Attempts (...) to rescue these theories by claiming that there is a structure in the olfactory system that is functionally equivalent to the thalamus in the visual system, such as the olfactory bulb or the olfactory cortex, are also shown to fail. If we wish to understand consciousness, we have to wake up and smell it. (shrink)

It is part of the phenomenology of perceptual experiences that objects seem to be presented to us. The first guide to objects is their perceptual presence. Further reflection shows that we take the objects of our perceptual experiences to be among the causes of our experiences. However, not all causes of the experience are also objects of the experience. This raises the question indicated in the title of this paper. We argue that taking phenomenal presence as the guide to the (...) objects of perception, we can see that at least in two sensory modalities, smell and touch, there is no uniform answer to this question. The objects of olfactory and tactile experiences can move along the causal chain. Accordingly, the content of olfactory and tactile experience may vary. (shrink)

When we experience the world – see, hear, feel, taste, or smell things – we gain all sorts of knowledge about the things around us. And this knowledge figures heavily in our reasoning about the world – about what to think and do in response to it. But what is the nature of this knowledge? On one commonly held view, all knowledge is constituted by beliefs in propositions. But in this paper I argue against this view. I argue that some (...) knowledge is constituted, not by beliefs in propositions, but by awareness of properties and objects. To make my case, I focus on the role of visual perception in reasoning. I start by introducing a principle about the relationship between knowledge and reasoning, which says that to learn something new by reasoning, one must know the bases of one’s reasoning. Then I argue that in some cases of genuine, knowledge-conferring reasoning, the bases of our reasoning are not propositions that we believe; rather, they’re properties or objects that we see. Thus, I conclude that some such knowledge is non-propositional and is rather what some call “knowledge of things”. (shrink)

Brain activity determines which relations between objects in the environment are perceived as differences and similarities in colour, smell, sound, etc. According to selectionism, brain activity does not create those relations; it only selects which of them are perceptually available to the subject on a given occasion. In effect, selectionism entails that perceptual experience is diaphanous, i.e. that sameness and difference in the phenomenal character of experience is exhausted by sameness and difference in the perceived items. It has been argued (...) that diaphaneity is undermined by phenomenological considerations and empirical evidence. This paper considers five prominent arguments of this sort and shows that none of them succeeds. (shrink)

How many senses do humans possess? Five external senses, as most cultures have it—sight, hearing, touch, smell, and taste? Should proprioception, kinaesthesia, thirst, and pain be included, under the rubric bodily sense? What about the perception of time and the sense of number? Such questions reduce to two. 1. How do we distinguish a sense from other sorts of information-receiving faculties? 2. By what principle do we distinguish the senses? Aristotle discussed these questions in the De Anima. H. P. Grice (...) revived them in 1967. More recently, they have taken on fresh interest as a result of a collection of essays edited by Fiona Macpherson. This entry reviews some approaches to these questions and advances some new ideas for the reader’s consideration. It proposes that the senses constitute an integrated learning system, membership in which answers question 1. It also proposes that the modalities can be distinguished from one another in two ways, by the means of information pick-up and by the kinds of activity that a perceiver undertakes to make use of them. (shrink)

While there is a growing philosophical interest in analysing olfactory experiences, the mereological structure of odours considered in respect of how they are perceptually experienced has not yet been extensively investigated. The paper argues that odours are perceptually experienced as having a mereological structure, but this structure is significantly different from the spatial mereological structure of visually experienced objects. Most importantly, in the case of the olfactory part-structure, the classical weak supplementation principle is not satisfied. This thesis is justified by (...) referring to empirical results in olfactory science concerning the human ability to identify components in complex olfactory stimuli. Further, it is shown how differences between olfactory and visual mereologies may arise from the way in which these modalities represent space. (shrink)

Aristotle sometimes claims that the perception of special perceptibles by their proper sense is unerring. This claim is striking, since it might seem that we quite often misperceive things like colours, sounds and smells. Aristotle also claims that the perception of common perceptibles is more prone to error than the perception of special perceptibles. This is puzzling in its own right, and also places constraints on the interpretation of. I argue that reading Alexander of Aphrodisias on perceptual error can help (...) to make good sense of both of Aristotle’s claims. (shrink)

Sense experience, naïvely conceived, is a way of knowing perceptible properties: the colors, sounds, smells, flavors, and textures in our perceptual environment. So conceived, ordinary experience presents the perceiver with the essential nature of a property like Sky Blue or Middle C, such that how the property appears in experience is identical to how it essentially is. In antiquity, as today, it was controversial whether sense experience could meet the conditions for knowledge implicit in this naïve conception. Aristotle was a (...) partisan in this debate, but his position is poorly understood. This dissertation examines how Aristotle’s perceptual psychology responds to ancient challenges to the naïve conception, and so articulates his defense of perceptual knowledge. -/- Aristotle’s defense relies on an ontology of “perceptual qualities"—a core class of perceptible properties—according to which those qualities, despite having a perceiver-independent essence rooted in the physics of causation and affection, nevertheless can be present in experience as they essentially are. Chapter 1 defends this realist and objectivist reading against competing interpretations, which overlook a crucial distinction between perceptual qualities and perceptual objects. Chapter 2 presents Aristotle’s ontology as a physicalism that uncharacteristically allows for perceptual qualities to appear in experience as they essentially are. -/- This ontology informs Aristotle’s account of the psychological conditions under which perceivers actually are presented with the essence of perceptual qualities. The locus of this account is an obscure passage where Aristotle purports to show that the senses “discriminate” perceptual qualities because the senses are “mean states” (An. 2.11, 424a5–7). Chapter 3 develops a comprehensive interpretation of the sensory mean state, which Chapter 4 uses to elucidate Aristotle’s argument for sensory discrimination. Sensory discrimination turns out to be a process in which the essence of a perceptual quality comes to be present in the affection it produces in a perceiver. For Aristotle, this shows that sense perception meets a condition for knowledge that his predecessors, including Plato, thought it could not meet. For in his view, but not in theirs, sense experience shares in both the truth and the essence of the qualities it perceives. (shrink)

The center of this investigation is the ‘real hard problem’ of phenomenal perception (Chalmers), i.e. of the qualitative kind of perception presenting the subject with forms, colors, smell, pleasurable or negative feelings etc.; the problem of Human consciousness, however, will explicitly not be treated. The ‘explanatory gap’ (Levine) complained by the philosophy of mind, that is to say the failure of all attempts to supply a neuronal explanation of experiences, is emergence-theoretically treated: Systems own properties and laws different from their (...) components; so the emergence concept shows promise also for the explanatory potential with respect to neuronal systems. Here the phenomenal character of perception is explained from the systemic co-action of perception and behavior, whereby also an interpretation is opened to Davidson’s anomal monism. Qualitative feelings, as is further shown, are not to be understood as needless ‘epiphenomena’, but as a necessary completion of per-ception when, as in the case of higher animals, the behavior is primarily controlled by phenomenal perception. (shrink)

Conscious experiences are characterized by mental qualities, such as those involved in seeing red, feeling pain, or smelling cinnamon. The standard framework for modeling mental qualities represents them via points in geometrical spaces, where distances between points inversely correspond to degrees of phenomenal similarity. This paper argues that the standard framework is structurally inadequate and develops a new framework that is more powerful and flexible. The core problem for the standard framework is that it cannot capture precision structure: for example, (...) consider the phenomenal contrast between seeing an object as crimson in foveal vision versus merely as red in peripheral vision. The solution I favor is to model mental qualities using regions, rather than points. I explain how this seemingly simple formal innovation not only provides a natural way of modeling precision, but also yields a variety of further theoretical fruits: it enables us to formulate novel hypotheses about the space and structures of mental qualities, formally differentiate two dimensions of phenomenal similarity, generate a quantitative model of the phenomenal sorites, and define a measure of discriminatory grain. A noteworthy consequence is that the structure of the mental qualities of conscious experiences is fundamentally different from the structure of the perceptible qualities of external objects. (shrink)