Recently, there has been a debate as to whether or not the principle of the identity of indiscernibles (the PII) is compatible with quantum physics. It is also sometimes argued that the answer to this question has implications for the debate over the tenability of ontic structural realism (OSR). The central aim of this paper is to establish what relationship there is (if any) between the PII and OSR. It is argued that one common interpretation of OSR is undermined if (...) the PII turns out to be false, since it is committed to a version of the bundle theory of objects, which implies the PII. However, if OSR is understood as the physical analogue of (sophisticated) mathematical structuralism then OSR does not imply the PII. It is further noted that it is (arguably) a virtue of OSR that it is compatible with a version of the PII for possible worlds. (shrink)

Our day-to-day experience of the world regularly brings us into contact with middlesized objects such as apples, dogs, and other human beings. These objects possess observable properties, properties that are available or accessible to the unaided senses, such as redness and roundness, as well as properties that are not so available, such as chemical ones. Both of these kinds of properties serve as valuable sources of information about our familiar middle-sized objects at least to the extent that they enable us (...) to understand the behaviours of those objects and their effects on each other and on us. I see the apple on the table before me, and in doing so I see its redness, its roundness, and so on. I do not see, but know that it has, a certain chemical constitution. The knowledge gained of the apple by means of both properties tells me something about the nature of that apple. In general, most, if not all, of the properties that objects in the observable world possess serve as the basis of our knowledge of such objects. But the subject-predicate form of much of our discourse and thought about objects suggests that substances are one kind of thing, properties another. We use subject terms such as names to identify objects, predicate terms to attribute properties to them. What, then, is it for an object to have a property? And what is the relation between an object and its properties? (shrink)

John Heil's new book (Heil 2003) is remarkable in many ways. In a concise, lucid and accessible manner, it develops a complete system of ontology with many strikingly original features and then applies that ontology to fundamental issues in the philosophy of mind, with illuminating results. Although Heil acknowledges his intellectual debts to C. B. Martin (p. viii), he is unduly modest about his own contribution to the development and application of this novel metaphysical system. A full examination of the (...) position that Heil defends would require a book in itself, so I shall limit myself to discussing some of its central themes and to explaining a few doubts that I have concerning some aspects of it. (shrink)

From an Ontological Point of View is a highly original and accessible exploration of fundamental questions about what there is. John Heil discusses such issues as whether the world includes levels of reality; the nature of objects and properties; the demands of realism; what makes things true; qualities, powers, and the relation these bear to one another. He advances an account of the fundamental constituents of the world around us, and applies this account to problems that have plagued recent work (...) in the philosophy of mind and metaphysics (color, intentionality, and the nature of consciousness). (shrink)

Steven French and Decio Krause examine the metaphysical foundations of quantum physics. They draw together historical, logical, and philosophical perspectives on the fundamental nature of quantum particles and offer new insights on a range of important issues. Focusing on the concepts of identity and individuality, the authors explore two alternative metaphysical views; according to one, quantum particles are no different from books, tables, and people in this respect; according to the other, they most certainly are. Each view comes with certain (...) costs attached and after describing their origins in the history of quantum theory, the authors carefully consider whether these costs are worth bearing. Recent contributions to these discussions are analyzed in detail and the authors present their own original perspective on the issues. The final chapter suggests how this perspective can be taken forward in the context of quantum field theory. (shrink)

The paper spells out five different accounts of the relationship between objects and relations three of which are versions of ontic structural realism. 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. (shrink)