ONTIC STRUCTRAL REALISM AND QUANTUM MECHANICS

Michaël Esfeld

Quentin Ruyant

Structural realism attempts to make a compromise between scientific realism and empiricism, by restricting our realist commitment to the relational structure of scientific theories. There are two main versions of the position: ontic, or epistemic. According to ontic structural realism, the nomological relations expressed by theories are the primitive entities of reality. This ontic version is motivated in particular by arguments to the effect that epistemic versions are not really distinct from mere empiricism. However according to some authors, it’s not clear that ontic structural realism can differentiate between physical and mathematical relations, and account for the relations between scientific theories and their experimental basis. These difficulties can be related to the measurement problem in quantum mechanics, which also concerns the link between theoretical models and experiments. It appears that epistemic structural realism is in a better position to respond to these difficulties. A compromise between both versions of structural realism could allow us to keep the advantages of both.

G. C. Ghirardi

James Ladyman, Lorenzo Lorenzetti

Three accounts of effective realism (ER) have been advanced to solve three problems for scientific realism: Fraser and Vickers (forthcoming) develop a version of ER about non-relativistic quantum mechanics that they argue is compatible with all the main realist versions (‘interpretations’) of quantum mechanics avoiding the problem of underdetermination among them; Williams (2019) and Fraser (2020b) propose ER about quantum field theory as a response to the problems facing realist interpretations; Robertson and Wilson (forthcoming) propose ER to deal with the dubious ontological status of the entities belonging to superseded theories. This paper argues for the unification of these proposals based on realism about modal structure and the idea of scale relativity of ontology developed by ontic structural realists. This solves problems some or all the accounts of ER face, especially that of making explicit in what way they are realist. Furthermore, we respond to a recent critique that has been raised against the ontic structural realist account of quantum mechanics that we employ.

Hans Primas

Ignacio Rojas

The aim of this work is to study the ontological thesis defended by Ontic Structural Realism, which, in general, states that the ontological commitments should be focused in the relations and not on objects. This would be a more coherent realist stance towards modern physical theories. In first place we will study the ontological conception defended by the Ontic Structural Realism, which, broadly speaking, postulates that the ontological focus should be placed on relations rather than on objects. This, in turn, would constitute a realistic interpretation of the current physical theories. Secondly, as a possible defense to the position stated by Ontic Structural Realism, the concept of non-supervenient relations will be studied and it will be argued that it is this type of relations that acquires a fundamental character in Quantum Mechanics, as, for example, in phenomena such as the so-called quantum entanglement.