Online research in philosophy

The old puzzle of material constitution has benefited from a lot of thorough discussion from the part of metaphysicians in the last thirty-odd years. The available solution options and their problems are by now familiar. They involve particular views on mainstream entities and relations of metaphysical inquiry, like objects, properties, events, causation, identity, supervenience, and so on. However, one might want to hope, together with some contemporary ontologists, most notably Roberto Casati and Achille Varzi (1994), that dealing with more peripheral entities is not without interest even when it comes to solving mainstream questions of metaphysics. This I am going to do here, with the puzzle of material constitution in the role of the mainstream ontological issue and shadows in the role of the minor, superficial, or peripheral entity.

Berkeley thinks that we only see the size, shape, location, and orientation of objects in virtue of the correlation between sight and touch. Shadows have all of these spatial properties and yet are intangible. In Seeing Dark Things (2008), Roy Sorensen argues that shadows provide a counterexample to Berkeley's theory of vision and, consequently, to his idealism. This paper shows that Berkeley can accept both that shadows are intangible and that they have spatial properties.

The Yale shadow puzzle1 purports to involve the ultimate incompatibility of the following plausible looking principles: (1) If X casts any shadow, then some light is falling directly on X. (2) Shadows cannot be cast through an opaque object. (3) Every shadow is the shadow of something. Imagine a high wall casting a shadow on the ground on a sunny day, and a little bird standing on the ground within the shadow cast by the wall. Is the shadow that is present on the ground under the bird –let’s mark it with S- the shadow of the bird, or (part of) the shadow of the wall? It cannot be the bird’s, by proposition (1), as the bird does not block any light. Neither can it be the wall’s, by proposition (2), as the wall cannot cast its shadow through the opaque bird. Yet, by proposition (3), it has to be the shadow of something. Roy Sorensen has offered neat looking solution to the puzzle; however, part of my goal in this paper is to show that this solutions doesn’t work for a new version of the Yale shadow puzzle, which I call “The Bilkent shadow puzzle”, in acknowledgment of my own academic affiliation. The remaining issue will be to offer a new solution that would cover both puzzles. As it will turn out, the solution is based on a peculiar understanding of the ontology of shadows.

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.

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.

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.

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.

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 “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.