Shadows

The dictionary tells you that a shadow is a dark area or volume caused by an opaque object blocking some light. The definition is correct, but we need to clarify a couple of its elements: darkness and blocking. The clarification leads to the view that to see a shadow is a degree of failing to see a surface. I will also argue that seeing a silhouette (i.e. a backlit object) is a particular way of failing to see an object. Thus (...) visual discriminability is not sufficient for seeing. Finally, I argue that comparative empirical research on shadows' contribution to amodal completion in apes and humans supports the view that humans, unlike apes, perceive shadows as shadows rather than as black objects, thus lending indirect support for my view that to see a shadow is a way and degree of failing to see a surface. (shrink)

In his famous book "Seeing Dark Things: The Philosophy of Shadows" (2008), Roy Sorensen put forward a ‘blocking theory of shadows’, a causal view on these entities according to which a shadow is an absence of light caused by blockage. This approach allows him to solve a quite famous riddle on shadows, ‘the Yale puzzle’, that was devised by Robert Fogelin in the late 1960s and that Sorensen presents in the form mentioned by Bas van Fraassen (1989). István Aranyosi has (...) recently criticized Sorensen’s solution to the Yale puzzle, on the grounds that it does not resist another version of the riddle, that Aranyosi calls ‘the Bilkent puzzle’. A new perspective on shadows, the ‘Material Exstitution View’, that allegedly permits to solve both puzzles, could be adopted as an alternative. In this paper I will show that Sorensen’s blockage theory can actually handle both the Yale and the Bilkent puzzle, plus another one that I put forward (‘the donut puzzle’), which instead is fatal to Aranyosi’s position. As Sorensen puts it, nothing aside from the original blockage of light is needed. (shrink)

According to Roy Sorensen, when one looks at the Moon, during a solar eclipse, what she sees is its inner part of the farther, reflective one, and not the always-facing-Earth side of our natural satellite. To make his point clearer, he put forward the famous example of a double eclipse involving the fictional planets Far and Near. From the observer’s vantage point, the two planets have the same apparent diameter and overlap. What the agent sees is a dark disk, but (...) believes that what she is seeing is Near, because Far is behind it. Sorensen claims that what she actually sees is planet Far and that the causal theory of perception explains why this is the case. Of course, this position stands against common sense. Sorensen shows that it counters Alvin Goldman’s renowned observation criteria too. Nonetheless, he maintains, since Near is causally idle and the agent does see something, the only possible conclusion is that she sees Far, pace Goldman – and common sense. In this paper, I try to demonstrate that Sorensen is wrong and that the correct solution to the eclipse riddle is that the observer sees Near. As a matter of fact, besides meeting common sense and Goldman’s observability criteria, Near can be legitimately be considered the object of a successful perceptual discrimination even in the light of the causal theory of perception. (shrink)

Many photographs seem to be images of absences: for instance, a photograph of a shadow seems to be an image of an absence, as shadows are plausibly thought of as being absences of light. Absence photography is puzzling, however, as, first, it is a common idea that photographs can only be images of things that have caused them, and, second, it is unclear whether absences can cause anything. In this paper, I look at various ways to unravel the puzzle. Along (...) the way, I also hope to cast some light on the idea that photography is a causal medium. (shrink)

Photography is often said to be an essentially causal medium. This paper addresses the role of causality in photography and argues for three main claims: (i) a causal theory of photography does not force us to say that images of backlit objects are photographs of the back surfaces of the said objects (as Roy Sorensen would have it); rather, (ii), such images, I suggest, are photographs of the objects and what Alva Noë would call their ‘looks’; (iii) the notion of (...) ‘looks’ furnishes us with a way to move closer to an answer to the question of the appropriate causal relation in photography. (shrink)

Shadows haunt the world of common sense by being “out there” independently of whether anyone is looking. Yet they are confi ned to a single sense: sight. Like ghosts, shadows evade tactile corroboration. They do not obey the laws governing material things.

Light and shadow create a conceptual pair which gives rise to a number of allusions in philosophy . Historically speaking, light is the paradigm of the Enlightenment . Significantly, in this paradigm certain vacillations appeared at the transition from the Age of Enlightenment to Romanticism: an appreciation of the shadow in the wake of the Romantic idealization of the dark side of human existence rises. Using the example of Adelbert von Chamisso’s work Peter Schlemihl’s Remarkable Story, the point of turn (...) from light to shadow can be fruitfully illustrated. This paper is a philosophical interpretation of the shadow alienation as loss of identity. Following this interpretation an attempt to define the structure of relationship between body and shadow as an identity relationship will be presented. By no means should shadow be degraded to a mere concomitant, it must be considered as an essential element of an identity-forming constellation . Although its appearance is characterised by short duration, the shadow belongs to the essential identity of the body, given that the body is defined exactly by the fact that it casts shadows when illuminated. The reciprocity of the light, the body and the shadow is therefore used to exemplify an alternative identity model, according to which a potential feature of an object on a particular occasion becomes necessary. With the concept of occasional identity it becomes possible to correct an ontologically rigid understanding of identity. (shrink)

This is a reply to Casey O'Callaghan and Jonathan Westphal’s comments on Seeing Dark Things: The Philosophy of Shadows. Both attempt to soften the blow to intuition that comes from the most controversial thesis of the book: we see the backs of back-lit objects. Each characterizes the viewing of silhouettes as a kind of marginal seeing that only discloses shapes, sizes and location. In response, photographs are presented to show that silhouettes are typically three-dimensional and they often have internal structure. (...) Consider the silhouette of a bird fluttering inside a cage; we see more than the outline of the cage. Orbiting this main point are subsidiary points about the distinction between shade and shadows, the nature of occlusion, the color black, and peculiarities of absent absences. (shrink)

Sorensen’s celebrated problem about the eclipse of Near and Far is given a solution in which what is seen is Far, silhouetted. Near cannot be seen, as it is in the shadow of Far. A silhouette is a shadow. The so–called Yale Puzzle is a linguistic confusion.

I discuss a solution to the Yale shadow puzzle, due to Roy Sorensen, based on the actual process theory of causation, and argue that it does not work in the case of a new version of the puzzle, which I call "the Bilkent shadow puzzle". I offer a picture of the ontology of shadows that constitute the basis for a new solution that uniformly applies to both puzzles.

In his latest book, Roy Sorensen offers a solution to a puzzle he put forward in an earlier article -The Disappearing Act. The puzzle involves various question about how the causal theory perception is to be applied to the case of seeing shadows. Sorensen argues that the puzzle should be taken as bringing out a new way of seeing shadows. I point out a problem for Sorensen’s solution, and offer and defend an alternative view, according to which the puzzle is (...) to be interpreted as showing a new way of seeing objects, in virtue of their contrast with light. (shrink)

Minor entities provide an interesting testbed for metaphysical theories, but also for investigating the structure of concepts, as their concepts appear to be tributary of different representational systems.

In “The Reappearing Act” István Aranyosi postulates a new way of seeing to solve a puzzle posed in “The Disappearing Act;” an object that is exactly shaded can be seen simply by virtue of its contrast with its environment – just like a shadow. This object need not reflect, refract, absorb or block light. To undermine the motive for this heretical innovation, I generalize the puzzle to situations involving inexact shading. Aranyosi cannot extend his solution to these variations because he (...) needs to conserve principles of camouflage. On the bright side, the solution to the puzzle that I propose in my book Seeing Dark Things does extend to these variations. (shrink)

Roy Sorensen’s adventure in Shadowland started with his prize-winning article, "Seeing Intersecting Eclipses" (published in The Journal of Philosophy, and chosen by the board of the Philosopher’s Annual as one of the ten best philosophy articles of 1999), which is the basis for the first two chapters in this book. The recipe adopted in that article is followed in most of the following thirteen chapters, five of them being based on Sorensen’s previous articles on the topic: start with an open (...) mind regarding the existence and causal efficacy of absences, shadows, i.e. absences of light, in our case, devise a riddle involving perception of such absences, and draw the consequences for the philosophy of perception and/or ontology. (shrink)

The eclipse riddle -- Seeing surfaces -- The disappearing act -- Spinning shadows -- Berkeley's shadow -- Para-reflections -- Para-refractions : shadowgrams and the black drop -- Goethe's colored shadows -- Filtows -- Holes in the light -- Black and blue -- Seeing in black and white -- We see in the dark -- Hearing silence.

Mainstream metaphysics has been preoccupied by inquiring into the nature of major kinds of entities, like objects, properties and events, while avoiding minor entities, like shadows or holes. However, one might want to hope that dealing with such minor entities could be profitable for even solving puzzles about major entities. I propose a new ontological puzzle, the Shadow of Constitution Puzzle, incorporating the old puzzle of material constitution, with shadows in the role of the minor entity to guide our approach (...) to the issues involved. I then analyze the standard answers to the original puzzle of constitution, in their role as potential solutions to the new puzzle. Finally, I discuss three views that can solve the proposed puzzle. (shrink)

This issue of The Monist is devoted to the metaphysics of lesser kinds, which is to say those kinds of entity that are not generally recognized as occupying a prominent position in the categorial structure of the world. Why bother? We offer two sorts of reason. The first is methodological. In mathematics, it is common practice to study certain functions (for instance) by considering limit cases: What if x = 0? What if x is larger than any assigned value? Physics, (...) too, often studies the (idealized) initial and boundary conditions of a given system: What would happen in the case of a perfect sphere, or a perfectly black body? In the cognitive sciences, research often thrives on the analysis of cognitive errors, perceptual illusions, brain pathologies. Also in logic one can learn a lot by studying special, anomalous scenarios such as those exhibited by the paradoxes: it is unlikely that we actually find ourselves in a soritical context, or in a liar-like situation, but the fact that we might—or simply the fact that we can conceive of such a possibility—is important enough to deserve careful consideration. In short, the odd, the unfamiliar, the extra-ordinary, the limit cases are perfectly at home in scientific and more broadly intellectual discourse at various levels, where they can be fruitfully engaged in a sophisticated way (witness the existence of specific confining and managing strategies for dealing with them); and they are important precisely because they instruct us concerning the normal, the obvious, and the paradigmatic. The same goes for metaphysics, we submit. Although its major concern is, naturally, with such core entities as substances, properties, or hunks of solid matter, a lot may be learned by paying attention to those limit cases where we find ourselves dealing with entities of much lesser kinds, whether real or putative. (shrink)

If a spinning sphere casts a shadow, does the shadow also spin? This riddle is the point of departure for an investigation into the nature of shadow movement. A general theory of motion will encompass all moving things, not just physical objects. Ultimately, I argue that round shadows do indeed spin. Shadows are followers of the objects that cast them. Parts of the shadow correspond to parts of the leader, so motion of the caster's parts accounts for motions of the (...) shadow's parts. I conclude with a discussion of how the dynamic aspects of shadows impose subtle constraints on other puzzles about shadows. (shrink)

We show that cast shadows can have a significant influence on the speed of visual search. In particular, we find that search based on the shape of a region is affected when the region is darker than the background and corresponds to a shadow formed by lighting from above. Results support the proposal that an early-level system rapidly identifies regions as shadows and then discounts them, making their shapes more difficult to access. Several constraints used by this system are mapped (...) out, including constraints on the luminance and texture of the shadow region, and on the nature of the item casting the shadow. Among other things, this system is found to distinguish between line elements (items containing only edges) and surface elements (items containing visible surfaces), with only the latter deemed capable of casting a shadow. (shrink)

The relationships between art and cognition constitute a very wide set of largely unexplored and at times undefined or much too speculative problems. The field is narrowed down by imposing some constraints. It is proposed that the depiction of cast shadows, in its early history, could provide an ideal case study which conforms to the constraints. This paper addresses some methodological problems of the study of this case. A sample of relevant Renaissance images is discussed. A typology of depicted cast (...) shadows is proposed upon which further empirical research could be built. (shrink)

Roy Sorensen has discussed a scenario he calls 'the Disappearing Act', introduced a puzzle based on this scenario, and offered a solution to this puzzle. We argue against Sorensen's solution and offer our own.

Imagine a child playing in the afternoon sun, suddenly jerking her arm one way then the other, trying to catch her shadow out. The game, the child soon learns, is one that she can never win. Her shadow moves the moment she does. Such childish games father common sense wisdom; when things move, so do their shadows. Or do they? A spinning sphere casts a shadow. But does its shadow also spin? The question takes you by surprise. Surely not? you (...) think. But then again, why not? This is the trope of Sorensen’s work. A seemingly simple phenomenon is probed in just the right way and, without warning, you are unsure what to say. (shrink)