In the context of discussions about the nature of ‘identical particles’ and the status of Leibniz’s Principle of the Identity of Indiscernibles in Quantum Mechanics, a novel kind of physical discernibility has recently been proposed, which we call witness-discernibility. We inquire into how witness-discernibility relates to known kinds of discernibility. Our conclusion will be that for a wide variety of cases, including the intended quantum-mechanical ones, witness-discernibility collapses extensionally to absolute discernibility, that is, to discernibility by properties.

When people deny that there are objects of a certain kind, they normally take this to be a reason to stop speaking as if such objects existed. For instance, when atheists deny the existence of God, they take this to be a reason to stop speaking about God’s will or His mercy. Or, to take a more mundane example, when people deny that there are round squares or that there are unicorns, they take this to be a reason to stop (...) speaking as if rounds squares or unicorns existed. (shrink)

My thesis discusses the unique challenge that platonistic mathematics poses to philosophical naturalism. It has two main parts. ;The first part discusses the three most important approaches to my problem found in the literature: First, W. V. Quine's holistic empiricist defense of mathematical platonism; then, the nominalists' argument that mathematical platonism is naturalistically unacceptable; and finally, a radical form of naturalism, due to John Burgess and Penelope Maddy, which dismisses any philosophical criticism of a successful science such as mathematics. I (...) find faults with all of these approaches. ;The second part attempts to do better. First, I develop an improved epistemological challenge to mathematical platonism. Roughly, this challenge asks for an account of what mathematicians' justification for believing in platonistic mathematics consists in. I argue this challenge is immune to the criticism I leveled against the traditional challenges. To show that it has bite, I apply this challenge to Quine's philosophy of mathematics. I argue this shows that Quine must invoke, in addition to his confirmational holism, a semantic indeterminacy thesis that is so radical as to be implausible. Finally, I attempt to develop a better response to the improved challenge. I defend an unorthodox view of the concept of an object and argue this makes room for a neo-Dedekindian view of mathematical objects which identifies mathematical existence with the logical coherence of the theory describing the structure in question. This view transforms metaphysical and epistemological questions about mathematical objects into corresponding, but more tractable questions about the logical notion of coherence. (shrink)

Is the natural number 3 identical with the Roman emperor Julius Caesar? In Grundlagen Frege raised some peculiar questions of this sort.1 There are two kinds of intuitions regarding such questions. On the one hand, these questions seem not only to be pointless but to be downright meaningless. Regardless of how much arithmetic one studies, no answer to the opening question will be forthcoming. Arithmetic tells us that 3 is the successor of 2 and that it is prime, but not (...) whether it is identical with Caesar. So questions concerning the identity of numbers and people seem not to be provided for. On the other hand, it seems that the opening question must be answered negatively. For numbers are not the sorts of things that can be identical with people. In fact, since the number 3 is an abstract object and Caesar is not, it follows by Leibniz’s law that they are not identical. (shrink)

A research biobank is a collection of personal health and lifestyle information, including genetic samples of yet unknown but possibly large information potential about the participant. For the participants, the risk of taking part is not bodily harm but infringements of their privacy and the harmful consequences such infringements might have. But what do we mean by privacy? Which harms are we talking about? To address such questions we need to get a grip on what privacy is all about and (...) aim for a fruitful perspective on the issues of property and privacy rights in the context of biobanking. This paper argues that the limits and handling of private matters is determined in specific social relations. The crucial point is thus to determine which information and activities are or are not the legitimate concern of others. Privacy and property rights should be seen as balanced by duties, that is as inherently relational interests extending into the public sphere, rather than to see these rights as the control of an object—for instance the participant’s biobank material. (shrink)

Quantum mechanics tells us that states involving indistinguishable fermions must be antisymmetrized. This is often taken to mean that indistinguishable fermions are always entangled. We consider several notions of entanglement and argue that on the best of them, indistinguishable fermions are not always entangled. We also present a simple but unconventional way of representing fermionic states that allows us to maintain a link between entanglement and non-factorizability.

Oystein Linnebo's book Thin Objects is partly devoted to defending the view that some objects are “thin” in that their existence does not impose any substantive demands on the world. In this paper, I discuss the concern that the defense relies on there being entities that serve as the referents of predicates. Linnebo thus seems to assume the thinness of those entities. In the course of my discussion, I also discuss what Linnebo says about the role of criteria of identity (...) in his discussion of reference and existence. (shrink)

Having its seeds in the 2nd International Lauener Symposium held in honour of Dagfinn Follesdal, the present collection contains a rich, kaleidoscopic ensemble of previously unpublished contributions by leading authors, representing diverse approaches to a variety of philosophical themes on which Follesdal has had a longstanding, formative impact. Follesdal himself contributes an orientating essay continuing to develop his pioneering theory of reference as well as in-depth commentaries on each of the other authors elaborated papers plus candid answers in the added (...) interview. The volume assembles a wealth of original articles containing in part direct discussions of Follesdal s work and covering a broad range of topics like subjectivity, intersubjectivity, objectivity, rationality, logics and mathematics, choice theory, values, modalities, intentionality, individuation, perception, communication, meaning, reference, the slingshot, one- and two-sorted semantics, evidence, neuropsychology, space and time, science and society, methodology, fallibilism, the relative a priori, justification, holism, the life-world, reflective equilibrium, empathy, and ethics. Moreover the book includes an incisive memoir of Follesdal the philosopher as well as a spanning interview with him, which are both critically directing toward Follesdal s subtly differentiated understanding of the dynamic philosophical horizon he shares in. With contributions from Dagfinn Follesdal, Charles Parsons, Patrick Suppes, Jon Elster, John Perry, Michael Friedman, Dag Prawitz, Wilhelm K. Essler, David Woodruff Smith, Olav Gjelsvik, Graciela De Pierris, Nils Roll-Hansen, Christian Beyer, Oystein Linnebo, Michael Frauchiger. Excerpt Open publication". (shrink)

It is impossible not to discuss the question of time, at least for the philosophy of religion. However, to discuss the question of time is equally impossible, as the various perspectives presented in this volume show. Then what is time? Time is not, and yet everything is within time. Time is, but neither substance nor pure form. Being a dimension of all Being, not even God could or would withdraw from time. The authors of the contributions to this volume discuss (...) the unavoidability of time and its paradoxes, not the least with the purpose of giving time, as a recurring topic for the philosophy of religion. Contributors: Joseph Ballan, Jonna Bornemark, Oystein Brekke, Rebecca Comay, Iben Damgaard, Arne Gron, Jan-Olav Henriksen, Marius Timmann Mjaaland, Carsten Pallesen, Ulrik Houlind Rasmussen, Werner Stegmaier, Philipp Stoellger, Claudia Welz. (shrink)