Online research in philosophy

Benjamin Callard has recently suggested that causation between Platonic objects—standardly understood as atemporal and non-spatial—and spatio-temporal objects is not ‘a priori’ unintelligible. He considers the reasons some have given for its purported unintelligibility: apparent impossibility of energy transference, absence of physical contact, etc. He suggests that these considerations fail to rule out a priori Platonic-object causation. However, he has overlooked one important issue. Platonic objects must causally affect different objects differently, and different Platonic objects must causally affect the same objects differently. How are Platonic objects—ones outside space and time—supposed to do that? CiteULike    Connotea    Del.icio.us    What's this?

In the correspondence with Clarke, Leibniz proposes to construe physical theory in terms of physical (spatio-temporal) relations between physical objects, thus avoiding incorporation of infinite totalities of abstract entities (such as Newtonian space) in physical ontology. It has generally been felt that this proposal cannot be carried out. I demonstrate an equivalence between formulations postulating space-time as an infinite totality and formulations allowing only possible spatio-temporal relations of physical (point-) objects. The resulting rigorous formulations of physical theory may be seen to follow Leibniz' suggestion quite closely. On the other hand, physical assumptions implicit in the postulation of space-time totalities are made explicit in the reconstruction of the space-time versions from the physical-relation versions.

This provocative new book attempts to resolve traditional problems of identity over time. It seeks to answer such questions as "How is it that an object can survive change?" and "How much change can an object undergo without being destroyed?" To answer these questions Professor Heller presents a completely new theory about the nature of physical objects and about the relationship between our language and the physical world. According to his theory, the only actually existing physical entities are what the author calls "hunks," four dimensional objects extending across time and space. This is a major new contribution to ontological debate and will be essential reading for all philosophers concerned with metaphysics.

Because the visual system cannot process all of the objects, colors, and features present in a visual scene, visual attention allows some visual stimuli to be selected and processed over others. Most research on visual attention has focused on spatial or location-based attention, in which the locations occupied by stimuli are selected for further processing. Recent research, however, has demonstrated the importance of objects in organizing (or segregating) visual scenes and guiding attentional selection. Because of the long history of spatial attention research, theories of spatial attention are more mature than theories of other visual processes, such as object segregation and object attention. In the present paper, I outline a biased competition account of object segregation and attention, following similar accounts that have been developed for spatial attention (Desimone and Duncan, 1995). In my biased competition account, I seek to understand how some objects can be segregated and selected over other objects in a complex visual scene. Under this account, there are two sources of visual information that allow an object to be processed over other objects: bottom-up information carried by the physical stimulus and top-down information based on an observer's goals. I use the biased competition account to combine many diverse findings from the object segregation and attention literatures into a common framework.

John Foster addresses the question: what is it to perceive a physical object? He rejects the view that we perceive such objects directly, and argues for a new version of the traditional empiricist account, which locates the immediate objects of perception in the mind. But this account seems to imply that we do not perceive physical objects at all. Foster offers a surprising solution, which involves embracing an idealist view of the physical world.

Byrne & Hilbert defend color realism, which assumes that: (a) colors are properties of objects; (b) these objects are physical; hence, (c) colors are physical properties. I accept (a), agree that in a certain sense (b) can be defended, but reject (c). Colors are properties of perceptual objects – which also have underlying physical properties – but they are not physical properties.

The paper spells out five different accounts of the relationship between objects and relations three of which are versions of ontic structural realism (OSR). We argue that the distinction between objects and properties, including relations, is merely a conceptual one by contrast to an ontological one: properties, including relations, are modes, that is the concrete, particular ways in which objects exist. We then set out moderate OSR as the view according to which irreducible relations are central ways in which the fundamental physical objects exist. Physical structures thus consist in objects for whom it is essential that they are related in certain ways. There hence are objects, but they do not possess an intrinsic identity. This view can also admit intrinsic properties as ways in which objects exist provided that these do not amount to identity conditions for the objects. Finally, we indicate how this view can take objective modality into account.

Ir IS winmx HELD that the capacity for spatial thought depends upon the ability to refer to physical things. The argument is that the identification of places depends upon the identification of things; places in themselves are all very much alike and can be distinguished only by their spatial relations to things. So one could not so much as think about places unless one could think about things (Strawson, 1959). It has to be acknowledged that our identifications of places are greatly enriched by our ability to refer to physical things. But, as we shall see, it is possible to identify places without identifying objects. 'Ihis raises the question whether there is any fundamental role that physical objects do play in our spatial thinking. I begin with the ways in which reference to physical objects enriches our capacity to identify places. We shall then consider whether reference to places as such demands reference to objects, and if not, what special role there might be for physical things in spatial thinking. A physical object has a certain causal structure. We can bring this out by reflecting on the way in which the properties of a physical thing affect its behaviour. Some of the properties of a thing just are propensities for it to behave in particular ways in particular circumstances. For example, being elastic, or brittle, are dispositional charac- 'teristics, they say that the thing will behave one way rather than another under pressure. But other properties of a thing, such as its size and..

When I perceive a physical object I am directly aware of something. This something may be called a sense?datum, leaving the question open whether it is indeed the physical object itself. Still, this question must be asked. It seems impossible that the sense?datum can be identical with the physical object for we do not always say we have different physical objects when we say we have different sense?data. On the other hand, the plain man does not think of the physical object as something other than the sense?datum. It is suggested that the plain man regards the sense?datum as in a sense identical with the physical object he is perceiving. But it is a peculiar sense of ?identity? which is in question, one which does not conform to the rules logicians lay down for this word.

Physical objects are the most familiar of all objects, and yet the concept of a physical object remains elusive. Any six-year-old can give you a dozen examples of physical objects, and most people with at least one undergraduate course in philosophy can also give examples of non-physical objects. But if asked to produce a definition of ‘physical object’ that adequately captures the distinction between the physical and the nonphysical, the average person can offer little more than hand-waving.