Gabriele Ferretti

In 1688 the Irish scientist and politician William Molyneux sent a letter to the philosopher John Locke. In it, he asked him a question: could someone who was born blind, and able to distinguish a globe and a cube by touch, be able to immediately distinguish and name these shapes by sight if given the ability to see? The philosophical puzzle offered in Molyneux’s letter fascinated not only Locke, but major thinkers such as Leibniz, Berkeley, Diderot, Reid, and numerous others including psychologists and cognitive scientists today. Does such a question represent a philosophical puzzle or a problem that can be solved by experimental tests? Can vision be fully restored after blindness? What is the relation between vision and touch? Are the senses linked through learning or bound at birth? Molyneux’s Question and the History of Philosophy is a major collection of essays that explore the long-standing issues Molyneux’s problem presents to philosophy of mind, perception and the senses. In addition, the volume considers the question from an interdisciplinary angle, examines the pre-history of the question, and aspects of it that have been ignored, such as perspectives from religion and disability. As such, Molyneux’s Question and the History of Philosophy presents a set of philosophically rich, empirically informed, and scientifically rigorous original investigations into this famous puzzle. It will be of great interest to students and researchers in philosophy, psychology, and the cognitive sciences including neuroscience, neurobiology and ophthalmology, as well as those studying the mind, perception and the senses.

Everyday visual experience constantly confronts us with things we can interact with in the real world. We literally feel the outside presence of physical objects in our environment via visual perceptual experience. The visual feeling of presence is a crucial feature of vision that is largely unexplored in the philosophy of perception, and poorly debated in vision neuroscience. The aim of this article is to investigate the feeling of presence. I suggest that visual feeling of presence depends on the visual representation of a very particular spatial relation with the object we interact with: the visual representation of absolute egocentric depth, which is due to stereoscopic vision.

According to an influential view, the detection of action possibilities and the selection of a plan for action are two segregated steps throughout the processing of visual information. This classical approach is committed with the assumption that two independent types of processing underlie visual perception: the semantic one, which is at the service of the identification of visually presented objects, and the pragmatic one which serves the execution of actions directed to specific parts of the same objects. However, as our knowledge of vision has improved over the years, this established view has turned out to be only an approximation. This paper sets out the details of a non-modularist approach to visual perception of action possibilities and explains how to resist the lure of cognitive segregation.

The most important question concerning picture perception is: what perceptual state are we in when we see an object in a picture? In order to answer this question, philosophers have used the results of the two visual systems model, according to which our visual system can be divided into two streams, a ventral stream for object recognition, allowing one to perceive from an allocentric frame of reference, and a dorsal stream for visually guided motor interaction, thus allowing one to perceive from an egocentric frame of reference. Following this model, philosophers denied that we can be in a dorsal perceptual state when perceiving a depicted object. This is because a depicted object is not physically graspable or manipulable and, in turn, it cannot be egocentrically localized, as a normal object, by the dorsal stream. Thus, the impossibility of manipulating depicted objects and of localizing them from an egocentric frame of reference has led some people to be sceptical about the possibility of a representation of action properties in the perception of objects in pictures, which pertains to the dorsal visual system. The aim of the present paper is to show that it is possible for the depicted object to be represented by dorsal perception. That means that we can ascribe action properties to depicted objects as well, even if depicted objects cannot be egocentrically localized—at least, not as much as normal objects can.

Habitual actions have a history of practice and repetition that frees us from attending to what we are doing. Nevertheless, habitual actions seem to be intentional. What does account for the intentionality of habitual actions if they are automatically performed and controlled? In this paper, we address a possible response to a particular version of this issue, that is, the problem of understanding how the intention to execute a habitual action, which comes in a propositional format, interlocks with motor representations, which come in a motoric-pragmatic format. In order to solve this issue, we propose an account according to which the propositional intentions and the motor representations related to our habitual actions interlock through executable action concepts. This allows us to maintain that habitual actions can be, at the same time, automatically initiated, performed, and controlled and, still, intentional.

Here is a crucial question in the contemporary philosophy of perception: how can we be aware of action properties? According to the perceptual view, we consciously see them: they are present in our visual phenomenology. However, this view faces some problems. First, I review these problems. Then, I propose an alternative view, according to which we are aware of action properties because we imagine them through a special form of imagery, which I call visuomotor imagery. My account is to be preferred as it offers an explanation of our awareness of action properties without generating all the problems that the perceptual view faces.

Intellectualists suggest that practical knowledge, or ‘knowing- how’, can be reduced to propositional knowledge, or ‘knowing-that’. Anti-intellectualists, on the contrary, suggest, following the original insights by Ryle, that such a reduction is not possible. Rejection of intellectualism can be proposed either by offering purely philosophical analytical arguments, or by recruiting empirical evidence from cognitive science about the nature of the mental representations involved in these two forms of knowledge. In this paper, I couple these two strategies in order to analyze some crucial reasons for which intellectualism seems not to be the best theory we have to correctly understand and describe practical knowledge. In particular, I will start from a specific philosophical account against intellectualism offered by Dickie :737–745, 2012), and suggest that it can be supported by current experimental results coming from motor neuroscience. The claim of the paper is that there is at least one kind of practical knowledge, which I call motor knowledge, and which is at the basis of the performance of skilled action, which cannot be reduced to propositional knowledge.

According to a shared functionalist view in philosophy of mind, a cognitive system, and cognitive function thereof, is based on the components of the organism it is realized by which, indeed, play a causal role in regulating our cognitive processes. This led philosophers to suggest also that, thus, cognition could be seen as an extended process, whose vehicle can extend not only outside the brain but also beyond bodily boundaries, on different kinds of devices. This is what we call the ‘Externally Extended Cognition Thesis.’ This notion has generated a lively debate. Here, we offer a novel notion of extended cognition, according to which cognition can be seen as being realized outside the brain, but still inside the body. This is what we call the ‘Internally Extended Cognition Thesis’. Not only our thesis but also our approach while defending it is innovative. The argument we offer is supported by recent empirical findings in the life sciences and biomedicine, which suggest that the gut microbiota’s activity has a functional role in regulating our cognitive processes and behaviors. In doing so, we embrace the holobiont-perspective, according to which it is possible to claim that what we call biological individuals are not autonomous entities with clear boundaries, but should rather be seen as networks of multiple interactions among species. Thus, by analyzing different sets of evidence in light of the holobiont-perspective, we argue that the gut microbiota could be seen as a component of our organism. On the basis of the philosophical interpretation of this evidence, however, we also suggest that there are no impediments standing the way of considering the gut microbiota also as a functional extension of our cognitive system. If so, this amounts to extending cognition out of ‘our skull’, though still confining it within ‘our body’: to ‘our gut’. This is an instance of the ‘Internally Extended Cognition Thesis,’ whose benefits for an original theory of extended cognition are discussed.

What mental states are required for an agent to know-how to perform an action? This question fuels one of the hottest debates in the current literature on philosophy of action. Answering this question means facing what we call here The Challenge of Format Dualism, which consists in establishing which is the format of the mental representations involved in practical knowledge and, in case they are given in more than one format, explaining how these different formats can interlock. This challenge has generated two parallel debates: the debate between Intellectualism and Anti-Intellectualism on the one hand, and the debate on the Interface Problem on the other. While the former is about whether practical knowledge can be considered a species of propositional knowledge, the latter investigates how motoric and propositional states can be related. Here we offer a unified account capable of explicitly analyzing those two problems within the same philosophical framework. Our account suggests a new way for solving the Interface Problem that paves the way for addressing the debate between Intellectualism and Anti-Intellectualism.

ABSTRACT:Are face-to-face perception and picture perception different perceptual phenomena? The question is controversial. On the one hand, philosophers have offered several solid arguments showing that, despite some resemblances, they are quite different perceptual phenomena and that pictures are special objects of perception. On the other hand, neuroscientists routinely use pictures in experimental settings as substitutes for normal objects, and this practice is successful in explaining how the human visual system works. But this seems to imply that face-to-face perception and picture perception are very similar, if not actually the same. How can we decide between these two opposite intuitions? Here I offer a regimentation of the notion of picture perception that can reconcile these two apparently conflicting ideas about pictures. It follows that philosophers and neuroscientists can maintain their respective stances without any theoretical conflict.

Philosophers have suggested that, in order to understand the particular visual state we are in during picture perception, we should focus on experimental results from vision neuroscience—in particular, on the most rigorous account of the functioning of the visual system that we have from vision neuroscience, namely, the ‘Two Visual Systems Model’. According to the initial version of this model, our visual system can be dissociated, from an anatomo-functional point of view, into two streams: a ventral stream subserving visual recognition, and a dorsal stream subserving the visual guidance of action. Following this model, philosophers have suggested that, since the two streams have different functions, they represent different properties of a picture. However, the original view proposed by the ‘Two Visual Systems Model’ about the presence of a strong anatomo-functional dissociation between the two streams has recently been questioned on both philosophical and experimental grounds. Indeed, the analysis of several new pieces of evidence seems to suggest that many visual representations in our visual system, related to different tasks, are the result of a deep functional interaction between the streams. In the light of the renewed status of the ‘Two Visual Systems Model’, also our best philosophical model of picture perception should be renewed, in order to take into account a view of the process of picture perception informed by the new evidence about such interaction. Despite this, no account fulfilling this role has been offered yet. The aim of the present paper is precisely to offer such an account. It does this by suggesting that the peculiar visual state we are in during picture perception is subserved by interstream interaction. This proposal allows us to rely on a rigorous philosophical account of picture perception that is, however, also based on the most recent results from neuroscience. Unless the explanation offered in this paper is endorsed, all the recent evidence from vision neuroscience will remain unexplained under our best empirically informed philosophical theory of picture perception.

When seeing a jaguar, we can see all the spots on its mantle without seeing a determinate number, N, of spots on the mantle. How is this visual phenomenon possible? Philosophers have tried to provide a reliable answer to this question, by recruiting evidence from vision science about the way attention works. Here we push this idea forward, by suggesting that an alternative and less complex solution, with respect to the one proposed in the literature, is possible. In particular, we argue that the puzzling visual phenomenon of 'seeing entities without seeing N-entities' strictly depends on the specific number of entities we are simultaneously attending to: a problematic scenario concerning this visual process arises only when the number of entities in the visual field exceeds a specific quantity. This depends, as we argue, on the fact that the nature of our visual content is modulated, in this perceptual scenario, by the limited way we can exercise visual attention on the properties of the objects of our perception. Differently from other accounts, our proposal allows us to properly define when and why such a problem arises, and explains why such a situation has traditionally been found to be so puzzling. Our idea is also well motivated by experimental results that so far have not been taken into account in the debate.

In this article, we propose a new account concerning the interlock between intentions and motor representations (henceforth: MRs), showing that the interface problem is not as deep as previously proposed. Before discussing our view, in the first section we report the ideas developed in the literature by those who have tried to solve this puzzle before us. The article proceeds as follows. In Sections 2 and 3, we address the views by Butterfill and Sinigaglia, and Mylopoulos and Pacherie, respectively, and argue that both solutions entail a translation between representational formats, which both accounts aim to avoid. In Section 4, we present our brand‐new claim, according to which intentions and MRs partially share the same motor format, inasmuch as executable action concepts are naturally represented in the agent's motor system together with the action's outcomes. Indeed, since intentions are constituted by executable action concepts and since there is evidence that action concepts are represented (and, thus, built) in the same motor format as action outcomes, the interlock between intentions and MRs no longer constitutes a problem. Then, in Section 5, we report empirical evidence in support of our claim, and before concluding, in Section 6 we briefly clarify our relations with two very recent accounts that criticized the proposals by Mylopoulos and Pacherie and Butterfill and Sinigaglia: Shepherd's and Burnston's. Finally, in Section 7, we offer some remarks about the philosophical idea defended here. The basic insight is that interface without translation is possible because action concepts are such stuff as MRs are made on.

Molyneux’s question famously asks about whether a newly sighted subject might immediately recognize, by sight alone, shapes that were already familiar to her from a tactile point of view. This paper addresses three crucial points concerning this puzzle. First, the presence of two different questions: the classic one concerning visual recognition and another one concerning vision-for-action. Second, the explicit distinction, reported in the literature, between ocular and cortical blindness. Third, the importance of making reference to our best neuroscientific account on vision, ‘the two visual systems model’, in order to better address Molyneux’s problem. Then, by offering a new, deeper analysis of the relation between, and, this paper suggests that the subjects of Molyneux’s two different questions show the same visual impairment as brain-damaged subjects with different lesions of the visual cortex. In particular, the subject of the first question shows the same impairment in visual recognition as a visual agnosic subject, while the subject of the second question shows the same visual impairment in visuomotor processing as an optic ataxic subject. These impairments still hold even if ocular processing is restored. Therefore, I suggest the following. For the first classic question, the required experimental setting cannot be properly reached. By contrast, concerning the second question, based on the interpretation we select, either the answer is negative, or, as with the first question, the experimental setting cannot be properly reached. This proposal constitutes, with the other approaches offered in the literature, a further attempt to tackle the enormous complexity of Molyneux’s puzzle.

Everyday life suggests that picture seeing is sometimes infused by an emotional charge. However, nobody has addressed the importance of explaining this emotional charge in picture perception. Even our best model of picture perception, the dorsal/ventral account of picture perception, which integrates the most important empirical results coming from our best model on vision in neuroscience, the two visual systems model, lacks a reference to this emotional charge. The aim of the present paper is to offer an account of picture perception that is able to regain and explain this neglected emotional charge. My claim is that, as for face-to-face perception, during picture perception, we are not only in a visual perceptual state, but also in an emotional state, which is directly connected to our visual perceptual state. I also show that it is possible to offer this integration while remaining in the philosophical/empirical framework of the dorsal/ventral account of picture perception, whose explanatory power is confirmed and improved.

Does action play any crucial role in our perception of pictures? The standard literature on picture perception has never explicitly tackled this question. This is for a simple reason. After all, objects in a picture seem to be static objects of perception. Thus, it might sound extremely controversial to say that action is crucial in picture perception. Contrary to this general intuitive stance, this paper defends, for the first time, the apparently very controversial claim, never addressed in the literature, that some of the specific and essential relations between vision and action make action (and its motoric basis) crucial in order for us to enter pictorial experience. I first discuss two ways in which vision and action are deeply linked, by describing the famous notions of Vision-for-Action and Sensorimotor Understanding. Then, I describe the special role they play in generating ordinary pictorial experience and suggest that, when we cannot rely on them while in front of a picture, we lose pictorial experience.

Philosophers suggested that usual picture perception requires the simultaneous occurrence of the perception of the surface and of the depicted object. However, there are special cases of picture perception, such as trompe l'oeil perception, in which, unlike in usual picture perception, the object looks like a real, present object we can interact with, of the kind we are usually acquainted with in face‐to‐face perception. While philosophers suggested that usual picture perception and trompe l'oeil perception must differ with respect to the perception of the surface, nobody has ever proposed a final explanatory account for such a difference. Here, I propose such an account. I consider the two possible options as candidates for the explanation of the illusory power of trompe l'oeil perception. The first is that, with trompe l'oeils, we perceive the surface unconsciously. The second is that, with trompe l'oeils, we cannot perceive the surface at all, that is, we cannot perceive it either consciously or unconsciously. I show that the second option is the unique plausible option, as it is in line with vision science, and with our received view about the nature of usual picture perception.

According to the received view in the philosophical literature on pictorial perception, when perceiving an object in a picture, we perceive both the picture’s surface and the depicted object, but the surface is only unconsciously represented. Furthermore, it is suggested, such unconscious representation does not need attention. This poses a crucial problem, as empirical research on visual attention shows that there can hardly be any visual representation, conscious or unconscious, without attention. Secondly, according to such a received view, when looking at a picture aesthetically, one both consciously represents and visually attends to both the depicted object and the picture’s surface simultaneously. Thus, contra the empirical research on attention, only conscious visual representations are coupled, by such current view, with attention. And this clearly poses a second problem, as this philosophical account is not in tune with what vision science tells us about the functioning of our visual system. Furthermore, this raises another crucial problem, namely, that of explaining why aesthetic experience of pictures does not feel odd or conflicting, since, as previously noted in the philosophical literature, and contra the received view, if we are simultaneously consciously perceiving both the picture’s surface and the depicted object, there seems to be two things, at the same time, in the foreground of one’s visual consciousness. But, if so, as suggested, this would lead to a conflicting spatial visual experience. This paper offers a new description of the role of visual attention in picture perception, which explains the difference between the usual and the aesthetic way of perceiving a depicted object, without facing the problems reported above. A crucial role in our new account is played by the notion of unconscious attention, the distinction between focal and distributed, as well as top-down and bottom-up visual attention and the relationship between visual attention and visual consciousness. The paper, thus, offers the first theory concerning the exercise of visual attention in pictorial perception that is both philosophically rigorous and empirically reliable.

In a recent paper, ‘Peripersonal perception in action’ (Synthese, 2018), Frédérique de Vignemont tackles the problem of defining what is peculiar to the visual perception of objects falling within the peripersonal space of the observer, i.e. the space immediately surrounding the body, and which is commonly described as the space in which action takes place. In this paper, I first discuss the proposal offered by de Vignemont about what characterizes peripersonal perception. Then, I suggest an extension of this account that offers a meticulous description of the nature of the Content of Peripersonal Visual Experience - a topic never explicitly considered in the philosophical literature on vision - by discussing some peculiar features of it that, as recognized also by de Vignemont’s account, still need to be explained. In particular, I offer a philosophical examination of the specificity of peripersonal visual experience, in relation to its phenomenological dimension, its optical mechanisms and its neurophysiological underpinnings, in the light of our best theories from vision science, and in comparison to the visual experience of other visual spaces.

Picture perception and ordinary perception of real objects differ in several respects. Two of their main differences are: Depicted objects are not perceived as present and We cannot perceive significant spatial shifts as we move with respect to them. Some special illusory pictures escape these visual effects obtained in usual picture perception. First, trompe l'oeil paintings violate : the depicted object looks, even momentarily, like a present object. Second, anamorphic paintings violate : they lead to appreciate spatial shifts resulting from movement. However, anamorphic paintings do not violate : they are still perceived as clearly pictorial, that is, nonpresent. What about the relation between trompe l'oeil paintings and? Do trompe l'oeils allow us to perceive spatial shifts? Nobody has ever focused on this aspect of trompe l'oeil perception. I offer the first speculation about this question. I suggest that, if we follow our most recent theories in philosophy and vision science about the mechanisms of picture perception, then, the only plausible answer, in line with phenomenological intuitions, is that, differently from nonillusory, usual picture perception, and similarly to ordinary perception, trompe l'oeil perception does allow us to perceive spatial shifts resulting from movement. I also discuss the philosophical implications of this claim.

Philosophers and cognitive scientists have been debating about the nature of practical knowledge in skilled action. A big challenge is that of establishing whether and how practical knowledge (knowledge-how) is influenced by, or related to propositional knowledge (knowledge-that). This becomes even more challenging when trying to understand how propositional and motor representations may cooperate in making action performance flexible, while also remaining rational. In this paper, we offer an account that explains how practical knowledge leads to the execution of our actions in a way that accounts for its relation to propositional knowledge, and with respect to the possibility of granting flexibility and rationality.

Philosophers suggested that usual picture perception requires the simultaneous occurrence of the perception of the surface and of the depicted object. However, there are special cases of picture perception, such as trompe l'oeil perception, in which, unlike in usual picture perception, the object looks like a real, present object we can interact with, of the kind we are usually acquainted with in face‐to‐face perception. While philosophers suggested that usual picture perception and trompe l'oeil perception must differ with respect to the perception of the surface, nobody has ever proposed a final explanatory account for such a difference. Here, I propose such an account. I consider the two possible options as candidates for the explanation of the illusory power of trompe l'oeil perception. The first is that, with trompe l'oeils, we perceive the surface unconsciously. The second is that, with trompe l'oeils, we cannot perceive the surface at all, that is, we cannot perceive it either consciously or unconsciously. I show that the second option is the unique plausible option, as it is in line with vision science, and with our received view about the nature of usual picture perception.

Mathematical models can be profitably used to establish whether our perception of the external world is accurate. Donald Hoffman and his collaborators have developed a promising mathematical framework within which this question can be addressed and which is based on an exhaustive taxonomy of the different possible relations between perceptual representations and the external world. After reformulating their framework by means of an improved formal system, we discuss their application of evolutionary game theory, which appears to show that an essentially anti-realistic perceptual strategy would in the long run biologically outcompete its rivals. We argue that their model does not take the crucial biological significance of environmental changes into due consideration and propose alternative models which do. We conclude that a partially realistic representation would be favoured in our models.

Philosophers have suggested that, in order to understand the particular visual state we are in during picture perception, we should focus on experimental results from vision neuroscience—in particular, on the most rigorous account of the functioning of the visual system that we have from vision neuroscience, namely, the ‘Two Visual Systems Model’. According to the initial version of this model, our visual system can be dissociated, from an anatomo-functional point of view, into two streams: a ventral stream subserving visual recognition, and a dorsal stream subserving the visual guidance of action. Following this model, philosophers have suggested that, since the two streams have different functions, they represent different properties of a picture. However, the original view proposed by the ‘Two Visual Systems Model’ about the presence of a strong anatomo-functional dissociation between the two streams has recently been questioned on both philosophical and experimental grounds. Indeed, the analysis of several new pieces of evidence seems to suggest that many visual representations in our visual system, related to different tasks, are the result of a deep functional interaction between the streams. In the light of the renewed status of the ‘Two Visual Systems Model’, also our best philosophical model of picture perception should be renewed, in order to take into account a view of the process of picture perception informed by the new evidence about such interaction. Despite this, no account fulfilling this role has been offered yet. The aim of the present paper is precisely to offer such an account. It does this by suggesting that the peculiar visual state we are in during picture perception is subserved by interstream interaction. This proposal allows us to rely on a rigorous philosophical account of picture perception that is, however, also based on the most recent results from neuroscience. Unless the explanation offered in this paper is endorsed, all the recent evidence from vision neuroscience will remain unexplained under our best empirically informed philosophical theory of picture perception.

Everyday visual experience constantly confronts us with things we can interact with in the real world. We literally feel the outside presence of physical objects in our environment via visual perceptual experience. The visual feeling of presence is a crucial feature of vision that is largely unexplored in the philosophy of perception, and poorly debated in vision neuroscience. The aim of this article is to investigate the feeling of presence. I suggest that visual feeling of presence depends on the visual representation of a very particular spatial relation with the object we interact with: the visual representation of absolute egocentric depth, which is due to stereoscopic vision.

Philosophers and neuroscientists often suggest that we perceptually represent objects and their properties. However, they start from very different background assumptions when they use the term “perceptual representation”. On the one hand, sometimes philosophers do not need to properly take into consideration the empirical evidence concerning the neural states subserving the representational perceptual processes they are talking about. On the other hand, neuroscientists do not rely on a meticulous definition of “perceptual representation” when they talk about this empirical evidence that is supposed to show that we perceptually represent such and such properties. It seems that, on both sides, something is missed. My aim is to show that, in the light of empirical evidence from neuroscience, the case of action properties is a good candidate in order to properly talk of perceptually represented properties. My claim is that the neurophysiological states encoding action properties are perceptual processes and that these perceptual processes are representational processes. That is, in the case of those neurophysiological states involved in the detection of action properties, it is correct to speak of perceptual representational states, and hence, ipso facto, of perceptually represented properties. First, I describe a reasonable and widely agreed upon conception of perceptual representation in the philosophical literature. Then, I report evidence from vision and motor neuroscience concerning the perception of action properties, which is subserved by the ventro-dorsal stream, a portion of the dorsal visual system. Finally, I show that a strong connection can be found between the philosophical idea of perceptual representation I have reported before and the neuroscientific evidence concerning the activity of the ventro-dorsal stream, whose job is, as said, to detect action properties.