Andreas Bartels

Wer sich den Relativitätstheorien mit einem philosophischen Blick nähert, stellt fest, dass die mehr als einhundert Jahre seit ihrer Entdeckung eine schwer überschaubare Vielzahl von Interpretationen hervorgebracht haben, die noch immer die Frage aufwerfen, was diese Theorien über die Natur von Raum und Zeit aussagen. Wer hat Recht, der Einstein des Jahres 1916, der in seinem Aufsatz Die Grundlage der allgemeinen Relativitätstheorie behauptet, die allgemeine Relativitätstheorie nehme „Raum und Zeit den letzten Rest physikalischer Gegenständlichkeit“ (Einstein 1916, S. 776), Tim Maudlin (2012), der in Philosophy of Physics. Space and Time fast einhundert Jahre später ausführt, die Theorie schreibe der Raumzeit eine objektive, intrinsische Geometrie zu, oder Harvey Brown (2005), der in Physical Relativity: Space-time structure from a dynamical perspective die Annahme einer intrinsischen geometrischen Natur von Raum und Zeit zurückweist und stattdessen die relativistischen Effekte bei Maßstäben und Uhren auf die Lorentz-Invarianz der Gesetze materieller Wechselwirkungen zurückführt?

How can the laws of nature, that determine how objects behave, be understood as natural objects themselves? The answer that transpires from the analysis of modern theories of the laws of nature is: laws of nature are due to the causal structure of our world. They express the causal efficiacy of fundamental properties of nature. In contrast to rivaling theories, this answer does justice to the fact that laws of nature determine the course of natural events without having to appeal to the strong assumption of necessarily acting forces. The modal force exerted by the laws of nature instead reflects a fundamental factual constitution of our world: fundamental properties like charge or mass exert their efficiacy in an unperturbed fashion, without influencing each other. The 'necessity' that laws of nature convey is hence compatible with their metaphysical contingency, the possibility of other, nomologically different worlds. The suggested theory connects laws of nature and causality in a new way: only in a temporally asymmetrical world can causality exist, and only in a causal world can fundamental properties exhibit those asymmetric relations that we call laws of nature.

The visual brain consists of several parallel, functionally specialized processing systems, each having several stages (nodes) which terminate their tasks at different times; consequently, simultaneously presented attributes are perceived at the same time if processed at the same node and at different times if processed by different nodes. Clinical evidence shows that these processing systems can act fairly autonomously. Damage restricted to one system compromises specifically the perception of the attribute that that system is specialized for; damage to a given node of a processing system that leaves earlier nodes intact results in a degraded perceptual capacity for the relevant attribute, which is directly related to the physiological capacities of the cells left intact by the damage. By contrast, a system that is spared when all others are damaged can function more or less normally. Moreover, internally created visual percepts-illusions, afterimages, imagery, and hallucinations-activate specifically the nodes specialized for the attribute perceived. Finally, anatomical evidence shows that there is no final integrator station in the brain, one which receives input from all visual areas; instead, each node has multiple outputs and no node is recipient only. Taken together, the above evidence leads us to propose that each node of a processing-perceptual system creates its own microconsciousness. We propose that, if any binding occurs to give us our integrated image of the visual world, it must be a binding between microconsciousnesses generated at different nodes. Since any two microconsciousnesses generated at any two nodes can be bound together, perceptual integration is not hierarchical, but parallel and postconscious. By contrast, the neural machinery conferring properties on those cells whose activity has a conscious correlate is hierarchical, and we refer to it as generative binding, to distinguish it from the binding that might occur between the microconsciousnesses

In the recent literature on concepts, two extreme positions concerning animal minds are predominant: the one that animals possess neither concepts nor beliefs, and the one that some animals possess concepts as well as beliefs. A characteristic feature of this controversy is the lack of consensus on the criteria for possessing a concept or having a belief. Addressing this deficit, we propose a new theory of concepts which takes recent case studies of complex animal behavior into account. The main aim of the paper is to present an epistemic theory of concepts and to defend a detailed theory of criteria for having concepts. The distinction between nonconceptual, conceptual, and propositional representations is inherent to this theory. Accordingly, it can be reasonably argued that some animals, e.g., grey parrots and apes, operate on conceptual representations.

What has the dispositional analysis of properties and laws (e.g. Molnar, Powers, Oxford University Press, Oxford, 2003; Mumford, Laws in nature, Routledge London, 2004; Bird, Nature’s metaphysics, Clarendon Press, Oxford, 2007) to offer to the scientific understanding of physical properties?—The article provides an answer to this question for the case of spacetime points and their metrical properties in General Relativity. The analysis shows that metrical properties are not ‘powers’, i.e. they cannot be understood as producing the effects of spacetime on matter with metaphysical necessity. Instead they possess categorical characteristics which, in connection with specific laws, explain those effects. Thus, the properties of spacetime do not favor the metaphysics of powers with respect to properties and laws

In this paper, I will defend the thesis that fundamental natural laws are distinguished from accidental empirical generalizations neither by metaphysical necessity (e.g. Ellis 1999, 2001; Bird in Analysis, 65(2), 147–155, 2005, 2007) nor by contingent necessitation (Armstrong 1983). The only sort of modal force that distinguishes natural laws, I will argue, arises from the peculiar physical property of mutual independence of elementary interactions exemplifying the laws. Mutual independence of elementary interactions means that their existence and their nature do not depend in any way on which other interactions presently occur. It is exactly this general physical property of elementary interactions in the actual world that provides natural laws with their specific modal force and grounds the experience of nature’s ‘recalcitrance’. Thus, the modal force of natural laws is explained by contingent non-modal properties of nature. In the second part of the paper, I deal with some alleged counterexamples to my approach: constraint laws, compositional laws, symmetry principles and conservation laws. These sorts of laws turn out to be compatible with my approach: constraint laws and compositional laws do not represent the dynamics of interaction-types by themselves, but only as constitutive parts of a complete set of equations, whereas symmetry principles and conservation laws do not represent any specific dynamics, but only impose general constraints on possible interactions.

In this paper Modern Essentialism is used to solve a problem of individuation of spacetime points in General Relativity that has been raised by a New Leibnizian Argument against spacetime substantivalism, elaborated by Earman and Norton. An earlier essentialistic solution, proposed by Maudlin, is criticized as being against both the spirit of metrical essentialism and the fundamental principles of General Relativity. I argue for a modified essentialistic account of spacetime points that avoids those obstacles.

fMRI is a tool to study brain function noninvasively that can reliably identify sites of neural involvement for a given task. However, to what extent can fMRI signals be related to measures obtained in electrophysiology? Can the blood-oxygen-level-dependent signal be interpreted as spatially pooled spiking activity? Here we combine knowledge from neurovascular coupling, functional imaging and neurophysiology to discuss whether fMRI has succeeded in demonstrating one of the most established functional properties in the visual brain, namely directional selectivity in the motion-processing region V5/ MT+. We also discuss differences of fMRI and electrophysiology in their sensitivity to distinct physiological processes. We conclude that fMRI constitutes a complement, not a poor-resolution substitute, to invasive techniques, and that it deserves interpretations that acknowledge its stand as a separate signal.

The paper discusses three different ways of explaining the referential stability of concepts of physics. In order to be successful, an approach to referential stability has to provide resources to understand what constitutes the difference between the birth of a new concept with a history of its own, and an innovative step occurring within the lifetime of a persisting concept with stable reference. According to Theodore Arabatzis' 'biographical' approach (Representing Electrons 2006), the historical continuity of representations of the electron manifests itself by the numerical stability of experimental parameters like the charge-to-mass ratio, and the continued acceptance of earlier experiments as manifestations of electron properties. I argue, against Arabatzis' approach, that the stability of experimental parameters justifies the assumption that there exists a chain of representations of a unique theoretical entity only if this stability occurs against the background of evidence for theoretical continuity. The Bain/Norton approach proposes to add exactly this element to the picture, but fails to reach its aim by focusing on formal similarities of Hamiltonians as an indicator of theoretical continuity. I shall argue that theoretical continuity has to be demonstrated rather on the level of particular solutions. This task is accomplished by the semantic embedding approach by means of defining a co-reference criterion for theoretical terms requiring the existence of semantic embedding relations between the terms that occur in particular solutions of different theories

Dieses Lehrbuch behandelt zentrale naturphilosophische Probleme, die durch Theorien der modernen Naturwissenschaften aufgeworfen werden. Es fragt, welches Bild von Raum, Zeit, Materie, Leben und Bewusstsein sich aus ihnen ergibt, aber auch nach den Konsequenzen der aktuellen Umweltkrise für unser praktisches Verhältnis zur Natur. Der Autor Prof. em. Dr. Andreas Bartels hat Mathematik, Physik und Philosophie studiert und ist emeritierter Professor für Natur- und Wissenschaftsphilosophie an der Universität Bonn.

The recent work of Paul Teller and Sunny Auyang in the philosophy of Quantum Field Theory (QFT) has stimulated the search for the fundamental entities in this theory. In QFT, the classical notion of a particle collapses. The theory does not only exclude classical, i.e., spatiotemporally identifiable particles, but it makes particles of the same type conceptually indistinguishable. Teller and Auyang have proposed competing ersatz-ontologies to account for the 'loss of particles': field quanta vs. field events. Both ontologies, however, suffer from serious defects. While quanta lack numerical identity, spatiotemporal localizability, and independence of basis-representations, events--if understood as concrete measurement events--are related to the theory only statistically. I propose an alternative solution: The entities of QFT are events of the type 'Quantum system, S, is in quantum state, Ψ '. These are not point events, but Davidsonian events, i.e., they can be identified by their location within the causal net of the world