One of the most exciting features in Foucault’s work is his analytics of power in terms of forms of visibility. It allows for a reflection on the conditions of seeing and thinking, thus triggering a seemingly paradoxical move: locating the limits of our perspectives entails simultaneously transgressing these limits. In a way, we decipher our own blind spot. Approaching Discipline and Punish through this perspective brings us to identify the digital subject as a characteristic figure of our time. In (...) contrast to its disciplinarian counterpart, it appears to be an active, though not necessarily political subject. The notion of visual citizenship will help us to go a step further and figure out what it could mean to challenge today’s surveilling gaze. (shrink)

First we give an overview about variants of visibility and related problems. Then we prove that some guarding and covering problems are NP-hard for ortho-polygons with holes, using a so-called vertex cover technique.

This paper mainly studies the communication performance of visible light communication link in fire smoke environment. Compared with the previous studies, this study no longer only considers a single wavelength and considers the influence of smoke and background light noise. Firstly, the variation of background light noise caused by sunlight during a day was analyzed, then signal-to-noise ratio and bit error rate of the visible light communication link in fire smoke environment with different visibility were calculated, and finally, the (...) variation of received power with the angle β between the LED optical axis and the communication link was analyzed. The results show that, during a day from 07:00 to 18:30, background light noise first increases and then decreases, BER changes in the same trend and reaches the maximum at about 13:00, while SNR changes in the opposite trend and reaches the minimum at about 13:00. When visibility is 100 m, the maximum difference of SNR between 7:00 and 13:00 is about 19 dB, and the maximum difference of BER is about 5.3E-10. At 7:00, the maximum difference of SNR is about 13 dB between the visibility of 1 m and the visibility of 100 m, and the maximum difference of BER is about 1.44E − 11, and received power decreases with the increase of β. In addition, SNR increases with visibility of fire smoke environment, and BER changes in the opposite trend. Lastly, in order to enhance the performance of visible light communication in fire smoke environment, this paper gives the transmitting power scheme. (shrink)

Recent discussions about violence against women have shifted their attention to specific forms of violence in relation to migration and Islam. In this article, I consider different modes of representing women's experiences in French immigrant communities. These representations relate to the French feminist movement Ni Putes Ni Soumises (neither whore nor submissive), a movement that in the early 2000s deplored both the sustained degradation of certain banlieue neighborhoods and also the charges and restrictions that this entails, particularly for young women. (...) Drawing on different narratives and images of women's painful experience, I consider, in a first step, how the question of representing violence against (post)migrant women is framed in terms of the tension between universality and particularity within French republicanism. In the next part of my argument, I bring into focus the question of how to access women's suffering. For a perspective on pain not as an interiorized, private experience but as an accessible complex of practices, articulations, memories, visions and social reconfigurations, I consider Smaïn Laacher's sociological study (2008) about written testimonies of violent experience that had been addressed by (post)migrant women to French women organizations such as Ni Putes Ni Soumises. I finally suggest reading women's accounts on violence not in relation to a universal discourse of rights, but as a political contestation of the naturalized order of representing violence, suffering and agency inside French banlieue communities. Drawing on Jacques Rancière's notion of dissensus, such a contestation can be staged through words by those who have no visibility in the representational order, words not to criticize the unaccomplished ideals of universal equality, but to create a universal community and a common language of experience in the mode of ‘as-if’. (shrink)

In his 'Inquiry', Reid claims, against Berkeley, that there is a science of the perspectival shapes of objects ('visible figures'): they are geometrically equivalent to shapes projected onto the surfaces of spheres. This claim should be understood as asserting that for every theorem regarding visible figures there is a corresponding theorem regarding spherical projections; the proof of the theorem regarding spherical projections can be used to construct a proof of the theorem regarding visible figures, and vice versa. I reconstruct Reid's (...) argument for this claim, and expose its mathematical underpinnings: it is successful, and depends on no empirical assumptions to which he was not entitled about the workings of the human eye. I also argue that, although Reid may or may not have been aware of it, the geometry of spherical projections is not the only geometry of visible figure. (shrink)

For the better part of the past decade, global social movements have drawn popular attention to the power of image production and acts of representation, particularly the ways ubiquitous cameras challenge the exercise of power This essay lays out a theoretical schema for interrogating a broader “politics of visibility” at work in the early twenty-first century, most readily apparent through the activities of smartphone-enabled and visually-savvy activists. As new media technologies have opened up new strategies of representation, these modes (...) of representation have been incorporated into existing media practices that delimit the ways in which the consequentiality of various movements and political projects can be understood. Theoretically revisiting the concept of visibility, this essay critiques the relationship between technology and the production of knowledge in media studies before arguing that the visibility of an event presages a consequentiality partially determined by the ways in which it is rendered perceptible and thus, intelligible. (shrink)

An explication is offered of Reid’s claim (discussed recently by Yaffe and others) that the geometry of the visual field is spherical geometry. It is shown that the sphere is the only surface whose geometry coincides, in a certain strong sense, with the geometry of visibles.

DNA profiling is a well-established technology for use in the criminal justice system, both in courtrooms and elsewhere. The fact that DNA profiles are based on non-coding DNA and do not reveal details about the physical appearance of an individual has contributed to the acceptability of this type of evidence. Its success in criminal investigation, combined with major innovations in the field of genetics, have contributed to a change of role for this type of evidence. Nowadays DNA evidence is not (...) merely about identification, where trace evidence is compared to a sample taken from a suspect. An ever-growing role is anticipated for DNA profiling as an investigative tool, a technique aimed at generating a suspect where there is none. One of these applications is the inference of visible traits. As this article will show, racial classifications are at the heart of this application. The Netherlands and its legal regulation of 'externally visible traits' will serve as an example. It will be shown that, to make this technology work, a large number of actors has to be enrolled and their articulations invited. This indicates that instead of a 'silent witness', a DNA profile should rather be seen as an 'articulate collective'. Based on two cases, I argue that the normativity of visible traits is context-dependent. Taking into account the practices in which technology is put to use alerts us to novel ethical questions raised by their application. (shrink)

Much evidence suggests that semantic characteristics of a message (e.g., the extent to which the message evokes thoughts of spatial or motor properties) and social characteristics of a speaking situation (e.g., whether there is a listener who can see the speaker) both influence how much speakers gesture. However, the Gesture as Simulated Action (GSA) framework (Hostetter & Alibali, ) predicts that these effects should not be independent but should interact such that the effect of visibility is lessened when a (...) message evokes strong thoughts of action. This study tested this claim by comparing the gesture rates produced by speakers as they described 24 nouns that vary in how strongly they evoke thoughts of action. Further, half of the words were described with visibility between speaker and listener blocked. The results demonstrated a significant interaction as predicted by the GSA framework. (shrink)

Hundreds of thousands of individuals experience traumatic injuries each year. Some are mild to moderate in nature and patients experience full functional recovery and little change to their physical appearance. Others result in enduring, if not permanent, changes in physical functioning and appearance. Reconstructive plastic surgical procedures are viable treatments options for many patients who have experienced the spectrum of traumatic injuries. The goal of these procedures is to restore physical functioning and reduce the psychosocial burden of living with an (...) appearance that may be viewed negatively by the patient or by others. Even after receipt of reconstructive procedures, many patients are left with residual disfigurement. In some, disability and disfigurement may be so profound that individuals are candidates for vascularized composite allotransplantation procedures, i.e., the transplantation of a vascularized human body part containing multiple tissue types as an anatomical and/or structural unit. This narrative review paper summarizes the literature on the psychosocial burden experienced by those who have visible disfigurement. While many of these individuals experience stigma and discrimination, relatively few studies have employed a stigma framework to understand the psychosocial sequelea. This paper briefly addresses this framework. Last, particular focus is given to the psychosocial issues of individuals with particularly severe injuries who are potential candidates for VCA procedures. (shrink)

According to the concept of direct parameter specification, nonconsciously registered information can be processed to the extent that it matches currently active intentions of a person. This prediction was tested and confirmed in the current study. Masked visual information provided by peripheral cues led to reaction time effects only if the information specified one of the required responses . Information delivered by the same masked cues that did not match the intentions was not used. However, the same information influenced RT (...) if it was provided by visible cues . The results suggest that the processing of nonconsciously registered information is flexible because it is susceptible to the changing intentions of a person. Yet, these processes are apparently restricted, as nonconsciously registered information cannot be used as easily for purposes not corresponding to the currently active intentions as better visible information. (shrink)

Thomas Reid (1710–1796) presented a two-dimensional geometry of the visual field in his Inquiry into the human mind (1764), whose axioms are different from those of Euclidean plane geometry. Reid’s ‘geometry of visibles’ is the same as the geometry of the surface of the sphere, described without reference to points and lines outside the surface itself. Interpreters of Reid seem to be divided in evaluating the significance of his geometry of visibles in the history of the discovery of non-Euclidean geometries. (...) The question will be reexamined with particular attention given to his unpublished manuscripts. These include comments on Saccheri’s work and Reid’s repeated attempts to derive Euclid’s parallel postulate from the axioms of incidence. (shrink)

Those who are familiar with the development of contemporary philosophy and in particular of phenomenology, may have frowned at the prospect of having to sit through a praise of visibility. Indeed, if there is any praise to be sung, it is not the visible but the invisible that should be its subject. The realm of the visible suffers from an intrinsic defect: it lacks the depth to resist the movement of appropriation implied in seeing, or more generally in perceiving. (...) It does not dispose of whatLevinas would call the infinity that could help it withstand the gaze that catches it and helps it contest the subject of that gaze its power. There is not enough of the event in it to “summon the subject outside of its autarky.” “The flat phenomenon and the subject to which nothing ever happens form a pair,” Rudolf Bernet writes in a paper with the telling title “Le phénomène et l’invisible (le regard).” It seems indeed left to the invisible to remediate the shortcomings of the eye that sees. Its task is to divest the subject who sees of a handicap it cannot compensate for on its own, — of a kind of Midas complex: whatever it encounters in the light that it throws on things, is fatally robbed of its alterity, leaving the seeing or perceiving subject alone in a solitude that is but the reverse side of the power by which it subjects whatever crosses its way. “The exteriority of light,” Levinas writes in this vein, “does not suffice for the liberation of the I that is its own prisoner.”. (shrink)

In a brief but remarkable section of the Inquiry into the Human Mind, Thomas Reid argued that the visual field is governed by principles other than the familiar theorems of Euclid—theorems we would nowadays classify as Riemannian. On the strength of this section, he has been credited by Norman Daniels, R. B. Angell, and others with discovering non-Euclidean geometry over half a century before the mathematicians—sixty years before Lobachevsky and ninety years before Riemann. I believe that Reid does indeed have (...) a fair claim to have discovered a non-Euclidean geometry. However, the real basis of Reid’s geometry of visibles is subtle and easy to misidentify. My main aim in what follows is to make clear what the real basis is, separating it from several fallacious or irrelevant considerations on which Reid may seem to be relying. A secondary aim is to air the worry that Reid’s case for his geometry can succeed only at the cost of compromising the achievement for which Reid is best known—his direct realist theory of perception. (shrink)

This paper considers an emerging practice whereby citizen’s use of ubiquitous and domesticated technologies enable a parallel form of criminal justice. Here, weaponised visibility supersedes police intervention as an appropriate response. Digital vigilantism is a user-led violation of privacy that not only transcends online/offline distinctions but also complicates relations of visibility and control between police and the public. This paper develops a theoretically nuanced and empirically grounded understanding of digital vigilantism in order to advance a research agenda in (...) this area of study. In addition to literature on vigilantism and citizen-led violence, this paper draws from key works in surveillance as well as visibility studies, 914–934, 2010) in order to situate how digital media affordances and cultures inform both the moral and organisational dimensions of digital vigilantism. Digital vigilantism is a process where citizens are collectively offended by other citizen activity, and coordinate retaliation on mobile devices and social platforms. The offending acts range from mild breaches of social protocol to terrorist acts and participation in riots. The vigilantism includes, but is not limited to a ‘naming and shaming’ type of visibility, where the target’s home address, work details and other highly sensitive details are published on a public site, followed by online as well as embodied harassment. The visibility produced through digital vigilantism is unwanted, intense and enduring. Such campaigns also further a merging of digital and physical spaces through the reproduction of localised and nationalist identities on global digital platforms as an impetus for privacy violations and breaches of fundamental rights. (shrink)

As the recent Ebola outbreak demonstrates, visibility is central to the shaping of political, medical, and socioeconomic decisions. The symposium in this issue of the Journal of Bioethical Inquiry explores the uneasy relationship between the necessity of making diseases visible, the mechanisms of legal and visual censorship, and the overall ethics of viewing and spectatorship, including the effects of media visibility on the perception of particular “marked” bodies. Scholarship across the disciplines of communication, anthropology, gender studies, and visual (...) studies, as well as a photographer’s visual essay and memorial reflection, throw light on various strategies of visualization and legitimation and link these to broader socioeconomic concerns. Questions of the ethics of spectatorship, such as how to evoke empathy in the representation of individuals’ suffering without perpetuating social and economic inequalities, are explored in individual, national, and global contexts, demonstrating how disease visibility intersects with a complex nexus of health, sexuality, and global/national politics. A sensible management of visibility—an “ecology of the visible”—can be productive of more viable ways of individual and collective engagement with those who suffer. (shrink)

I gave remarks at the Third International Summit on Human Genome Editing in London, UK on the first day for the section titled, “Sickle Cell Disease: A Case Study Affecting Millions.” It did not es...

In this paper, we make explicit the changing configurations of power relations that currently characterize the Brazilian Emergency Care System (SAMU) team in Belo Horizonte, Brazil. The SAMU is a recent innovation in Brazilian healthcare service delivery. A qualitative case study methodology was used to explore SAMU’s current organizational arrangements, specifically the power relations that have developed and that demonstrate internal team struggles over space and defense of particular occupational interests. The argument advanced in this paper is that these professionals (...) are developing their work in conditions of exposure, that is, they are always being observed by someone, and that such observational exposure provides the conditions whereby everyday emergency care practices are enacted such that practice is shaped by, as well as shapes, particular, yet recognizable power relationships. Data were collected through the observation of the SAMU’s work processes and through semi‐structured interviews. Research materials were analyzed using discourse analysis. In the emergency care process of work, visibility is actually embedded in the disciplinary context and can thus be analyzed as a technique applied to produce disciplined individuals through the simple mechanisms elaborated by Foucault such as hierarchical surveillance, normalizing judgment, and the examination. (shrink)

Sara Mills’ influential Foucauldian study of women’s travel writing, Discourses of Difference, heralded a turn from the consideration of individual female travellers as exceptions towards an analysis of the discursive pressures similarly exerted on all of them, through the awareness of normative expectations regarding the production and the reception of their writings. This article revisits panopticism in the genre by showing how travel writing reveals the intersection between the material plane and the discursive process. Through the parallel analysis of three (...) travel narratives, Anna Jameson’s Winter Studies and Summer Rambles in Canada, Isabella Bird’s A Lady’s Life in the Rocky Mountains, and Mary Kingsley’s Travels in West Africa, I show how their clothing and behaviour are enacted as signs of femininity for the benefit of their contemporaries, in texts whose diaristic form articulates the writing of the self and its exhibition to the public. I thus analyse how these travel narratives illustrate the intersection of the individual and the social in power relations and self-fashioning, and how their authors negotiate surveillance in gender performance. (shrink)

Thomas Reid argued that the geometrical properties of visible figures equal the geometrical properties of their projections on the inside of a sphere centred around the eye. In recent scholarship there are only a few suggestions of which sources might have inspired Reid. I point to a widely ignored body of early eighteenth-century literature – introductions into projective geometry, the use of celestial globes and astronomy – in which the model of the eye in the centre of a sphere was (...) immensely popular. Moreover, I argue that Reid's account results naturally from some astronomical doctrines in conjunction with George Berkeley's theory of vision. (shrink)

Chapter I: The Geometry of Visibles 1 . The N on- Euclidean Geometry of Visibles In the chapter "The Geometry of Visibles" in Inquiry into the Human Mind, ...

The subject of this investigation is the role of conventions in the formulation of Thomas Reid’s theory of the geometry of vision, which he calls the ‘geometry of visibles’. In particular, we will examine the work of N. Daniels and R. Angell who have alleged that, respectively, Reid’s ‘geometry of visibles’ and the geometry of the visual field are non-Euclidean. As will be demonstrated, however, the construction of any geometry of vision is subject to a choice of conventions regarding the (...) construction and assignment of its various properties, especially metric properties, and this fact undermines the claim for a unique non-Euclidean status for the geometry of vision. Finally, a suggestion is offered for trying to reconcile Reid’s direct realist theory of perception with his geometry of visibles.While Thomas Reid is well-known as the leading exponent of the Scottish ‘common-sense’ school of philosophy, his role in the history of geometry has only recently been drawing the attention of the scholarly community. In particular, several influential works, by N. Daniels and R. B. Angell, have claimed Reid as the discoverer of non-Euclidean geometry; an achievement, moreover, that pre-dates the geometries of Lobachevsky, Bolyai, and Gauss by over a half century. Reid’s alleged discovery appears within the context of his analysis of the geometry of the visual field, which he dubs the ‘geometry of visibles’. In summarizing the importance of Reid’s philosophy in this area, Daniels is led to conclude that ‘there can remain little doubt that Reid intends the geometry of visibles to be an alternative to Euclidean geometry’;1 while Angell, similarly inspired by Reid, draws a much stronger inference: ‘The geometry which precisely and naturally fits the actual configurations of the visual field is a non-Euclidean, two-dimensional, elliptical geometry. In substance, this thesis was advanced by Thomas Reid in 1764...’, 2 The significance of these findings has not gone unnoticed in mathematical and scientific circles, moreover, for Reid’s name is beginning to appear more frequently in historical surveys of the development of geometry and the theories of space., 3Implicit in the recent work on Reid’s ‘geometry of visibles’, or GOV, one can discern two closely related but distinct arguments: first, that Reid did in fact formulate a non-Euclidean geometry, and second, that the GOV is non-Euclidean. This essay will investigate mainly the latter claim, although a lengthy discussion will be accorded to the first. Overall, in contrast to the optimistic reports of a non-Euclidean GOV, it will be argued that there is a great deal of conceptual freedom in the construction of any geometry pertaining to the visual field. Rather than single out a non-Euclidean structure as the only geometry consistent with visual phenomena, an examination of Reid, Daniels, and Angell will reveal the crucial role of geometric ‘conventions’, especially of the metric sort, in the formulation of the GOV. Consequently, while a non-Euclidean geometry is consistent with Reid’s GOV, it is only one of many different geometrical structures that a GOV can possess. Angell’s theory that the GOV can only be construed as non-Euclidean, is thus incorrect. After an exploration of Reid’s theory and the alleged non-Euclidean nature of the GOV, in 1 and 2 respectively, the focus will turn to the tacit role of conventionalism in Daniels’ reconstruction of Reid’s GOV argument, and in the contemporary treatment of a non-Euclidean visual geometry offered by Angell. Finally, in the conclusion, a suggestion will be offered for a possible reconstruction of Reid’s GOV that does not violate his avowed ‘direct realist’ theory of perception, since this epistemological thesis largely prompted his formulation of the GOV. (shrink)

Drawing on work done by Helmholtz, I argue that Reid was in no position to infer that objects appear as if projected on the inner surface of a sphere, or that they have the geometric properties of such projections even though they do not look concave towards the eye. A careful consideration of the phenomena of visual experience, as further illuminated by the practice of visual artists, should have led him to conclude that the sides of visible appearances either look (...) straight, in which case their angles appear to approximate Euclidean measures, or their angles do not appear to approximate Euclidean measures for straight line figures, in which case their sides do not look straight. (shrink)

To challenge the Foucauldian legacy of Jeremy Bentham’s panopticon prison, scholars often highlight Bentham’s later writings on the democratic power of public opinion. In doing so, they reaffirm Bentham’s reputation as a unreserved proponent of transparency. To recover the limits of Bentham’s embrace of publicity, I examine the model of visibility exemplified by his designs for the Sotimion, a residence for unmarried, pregnant women. The Sotimion draws our attention to Bentham’s appreciation for concealment as a method of preventing individual (...) and social harms caused by publicity and his criticisms of ascetic sexual norms. By being able to see visitors without being seen by them, the residents of the Sotimion would have avoided social censure while continuing to meet with friends, family, and even lovers. The Sotimion designs eschewed the panoptic principle, the use of asymmetric surveillance to reform moral behavior, and offered what I call the “soteric principle,” the use of asymmetric surveillance to protect the observer from punishment. By comparing the Sotimion to the Magdalen Hospital for Penitent Prostitutes and Bentham’s discussions of panoptic institutions for women, I examine the Sotimion’s distinctiveness while acknowledging its normalizing effects for residents from lower socioeconomic classes. Just as the panopticon captured Bentham’s commitment to publicity, applying the soteric model to Bentham’s theory of public opinion highlights his commitment to secrecy for protecting critics of government abuses from retribution. (shrink)

In today’s world, Artificial Intelligence plays a central role in many decision-making processes. However, its use can lead to structural and epistemic injustices—especially in the context of healt...

A meta-analysis and an experiment show that the degree of compression of the in-depth dimension of visual space relative to the frontal dimension increases quickly as a function of the distance between the stimulus and the observer at first, but the rate of change slows beyond 7 m from the observer, reaching an apparent asymptote of about 50 %. In addition, the compression of visual space is greater for monocular and reduced cue conditions. The pattern of compression of the in-depth (...) dimension as a function of distance is similar to the ratio of in-depth to frontal visual angles of stimuli, but is not as extreme as this ratio would suggest, implying that observers are incapable of fully ignoring size information provided by cues to depth. Size and distance judgments may be described by an Affine transformation of physical space; however, the compression parameter in this model changes as a function of distance from the observer and other experimental conditions. (shrink)

Alone among surviving Athenian homicide orations, Antiphon'sOn the Murder of Herodesresembles a modern murder mystery. Antiphon's client, a Mytilenean named Euxitheus, tells a story of a stormy night, an isolated harbour, a drunken murder victim, a missing corpse, misleading bloodstains, forged documents and hints of political intrigue. And, like in any good whodunnit, Euxitheus insists that no one knows who the killer is. Although all the clues seem to point to him, he maintains that Herodes' relatives have manipulated the evidence (...) to make him seem guilty. We do not know whether Euxitheus succeeded in convincing his jurors, but the author of theLife of Antiphonattributed to Plutarch, who says that Antiphon was ‘adept in situations with no way out’ (ἐν τοῖς ἀπόροις τεχνικός), considersOn the Murder of Herodesone of Antiphon's finest compositions (832E, 833D). (shrink)

The Affect of good artworks can be difficult to explain or describe, particularly in relation to conceptual art. The experiential process of engaging with an artwork involves the spectator perceiving the physical art object as well as receiving a concept. For an aesthetic experience to result, or for the viewer to be affected, the artist must be skilled and the receiver must adopt the relevant attitude. Many theorists argue that the correct attitude to adopt is one that is objective and (...) ‘disinterested’. I argue that a ‘loving’ attitude, in the Iris Murdoch / Martha Nussbaum sense derived from an ethics of care / virtue ethics framework is also appropriate when engaging with art in order to achieve an aesthetic affect. This open, caring attitude requires the receiver to be receptive to the concepts contained within the work as well as its formal features. If the concepts implored are ethical or social, a disinterested attitude may impede the appropriate up-take of intended affect. Therefore, I argue that pure aesthetes are misguided when they take their ‘disinterested’ attitude too far and argue that ethical judgements do not apply to art qua art. If the artist is making an ethical point, or if the concept involved relies on ethics, then a caring critique is not a contradiction in terms; the viewer is encouraged to adopt multiple perspectives in order to get closer to an objective whole. I will explore the notion of affect through the art of a contemporary, conceptual Western Australian artist, Steven Morgana. (shrink)

In this paper, we provide a macro level analysis of the visibility of philosophy of science in the sciences over the last four decades. Our quantitative analysis of publications and citations of philosophy of science papers, published in 17 main journals representing the discipline, contributes to the longstanding debate on the influence of philosophy of science on the sciences. It reveals the global structure of relationships that philosophy of science maintains with science, technology, engineering and mathematics and social sciences (...) and humanities fields. Explored at the level of disciplines, journals and authors, this analysis of the relations between philosophy of science and a large and diversified array of disciplines allows us to answer several questions: what is the degree of openness of various disciplines to the specialized knowledge produced in philosophy of science? Which STEM and SSH fields and journals have privileged ties with philosophy of science? What are the characteristics, in terms of citation and publication patterns, of authors who get their philosophy of science papers cited outside their field? Complementing existing qualitative inquiries on the influence of specific authors, concepts or topics of philosophy of science, the bibliometric approach proposed in this paper offers a comprehensive portrait of the multiple relationships that links philosophy of science to the sciences. (shrink)

Thomas Reid claims to have learned of Idomenians, “an order of beings” in “sublunary regions” whose visual system is very much like ours except that they could detect only the direction of rays reaching their eyes, not the distance of origin. The properties of Idomenian vision are here examined in the light of the physiological optics of Reid’s time and of the scientific developments that have since augmented our knowledge of the discipline.

In this paper, I work out a five-stringed criticism of John Hattie’s theory of Visible Learning. First, I argue that the theory is a theory of evaluation that denies education as such. Second, I show that there are problems with the dependent variable, learning, i.e. the effect of a given intervention. Thirdly, I show that Hattie's theory belongs to the radical constructivist paradigm. Thus, the problems of constructivism, i.e. problems of normativity and the outside world, walks directly into Hattie’s concept (...) of teaching, resulting in a double breakdown of the essence of teaching. Fourth, I argue that Hattie’s concept of feedback has a centralizing trend which ultimately has the potential to transform the country’s educational activities into a big hierarchical and data-driven organism. Finally, I show that Hattie’s reference to Karl Popper’s theory of “three worlds” is based on a highly problematic reading, where Popper’s objective world is reduced to a subset of a radical subjectivity. (shrink)