Causality and the Modeling of the Measurement Process in Quantum Theory

In this paper we provide a general account of the causal models which attempt to provide a solution to the famous measurement problem of Quantum Mechanics (QM). We will argue that --leaving aside instrumentalism which restricts the physical meaning of QM to the algorithmic prediction of measurement outcomes-- the many interpretations which can be found in the literature can be distinguished through the way they model the measurement process, either in terms of the efficient cause or in terms of the final cause. We will discuss and analyze why both, 'final cause' and 'efficient cause' models, face severe difficulties to solve the measurement problem. In contradistinction to these schemes we will present a new model based on the immanent cause which, we will argue, provides an intuitive understanding of the measurement process in QM

Probabilistic Knowledge as Objective Knowledge in Quantum Mechanics: Potential Powers Instead of Actual Properties

In classical physics, probabilistic or statistical knowledge has been always related to ignorance or inaccurate subjective knowledge about an actual state of affairs. This idea has been extended to quantum mechanics through a completely incoherent interpretation of the Fermi-Dirac and Bose-Einstein statistics in terms of "strange" quantum particles. This interpretation, naturalized through a widespread "way of speaking" in the physics community, contradicts Born's physical account of {\Psi} as a "probability wave" which provides statistical information about outcomes that, in fact, cannot be interpreted in terms of 'ignorance about an actual state of affairs'. In the present paper we discuss how the metaphysics of actuality has played an essential role in limiting the possibilities of understating things differently. We propose instead a metaphysical scheme in terms of powers with definite potentia which allows us to consider quantum probability in a new light, namely, as providing objective knowledge about a potential state of affairs.Comment: 35 pages, no figures. To be published in Probing the Meaning of Quantum Mechanics, D. Aerts, C. de Ronde, H. Freytes and R. Giuntini (Eds.), World Scientific, Singapore, forthcoming. More comments welcome

Interpreting the Quantum Wave Function in Terms of 'Interacting Faculties'

In this article we discuss the problem of finding an interpretation of quantum mechanics which provides an objective account of physical reality. In the first place we discuss the problem of interpretation and analyze the importance of such an objective account in physics. In this context we present the problems which arise when interpreting the quantum wave function within the orthodox formulation of quantum mechanics. In connection to this critic, we expose the concept of 'entity' as an epistemological obstruction. In the second part of this paper we discuss the relation between actuality and potentiality in classical and quantum physics, and continue to present the concept of 'ontological potentiality' which is distinguished from the generic Aristotelian notion of potentiality in terms of 'becoming actual'. In this paper our main aim is to provide an objective interpretation of quantum mechanics which allows us to discuss the meaning of physical reality according to the theory. For this specific propose we present the concept of 'faculty' in place of the concept of 'entity'. Within our theory of faculties, we continue to discuss and interpret two paradigmatic experiments of quantum mechanics such as the double-slit and Schrodinger's cat.Comment: 34 page

Hilbert Space Quantum Mechanics is Contextual (Reply to R. B. Griffiths)

In a recent paper Griffiths [38] has argued, based on the consistent histories interpretation, that Hilbert space quantum mechanics (QM) is noncontextual. According to Griffiths the problem of contextuality disappears if the apparatus is "designed and operated by a competent experimentalist" and we accept the Single Framework Rule (SFR). We will argue from a representational realist stance that the conclusion is incorrect due to the misleading understanding provided by Griffiths to the meaning of quantum contextuality and its relation to physical reality and measurements. We will discuss how the quite general incomprehension of contextuality has its origin in the "objective-subjective omelette" created by Heisenberg and Bohr. We will argue that in order to unscramble the omelette we need to disentangle, firstly, representational realism from naive realism, secondly, ontology from epistemology, and thirdly, the different interpretational problems of QM. In this respect, we will analyze what should be considered as Meaningful Physical Statements (MPS) within a theory and will argue that Counterfactual Reasoning (CR) -considered by Griffiths as "tricky"- must be accepted as a necessary condition for any representational realist interpretation of QM. Finally we discuss what should be considered as a problem (and what not) in QM from a representational realist perspective.Comment: arXiv admin note: substantial text overlap with arXiv:1502.0531

Immanent Powers versus Causal Powers (Propensities, Latencies and Dispositions) in Quantum Mechanics

In this paper we compare two different notions of 'power', both of which attempt to provide a realist understanding of quantum mechanics grounded on the potential mode of existence. For this propose we will begin by introducing two different notions of potentiality present already within Aristotelian metaphysics, namely, irrational potentiality and rational potentiality. After discussing the role played by potentiality within classical and quantum mechanics, we will address the notion of causal power which is directly related to irrational potentiality and has been adopted by many interpretations of QM. We will then present the notion of immanent power which relates to rational potentiality and argue that this new concept presents important advantages regarding the possibilities it provides for understanding in a novel manner the theory of quanta. We end our paper with a comparison between both notions of 'power', stressing some radical differences between them.Comment: Forthcoming in: Probing the Meaning and Structure of Quantum Mechanics, D. Aerts, M.L. Dalla Chiara, C. de Ronde and D. Krause (Eds.), World Scientific, Singapore. arXiv admin note: text overlap with arXiv:1310.453