Realism and Underdetermination: Some Clues From the Practices-Up

Abstract

Recent attempts to turn Standard Quantum Theory (SQT) into a coherent representational system show considerable improvement over previous offerings, but such attempts still fail to settle important questions about the nature of material systems, as current theorizing about the latter effectively resolves into a multiplicity of incompatible statements about their nature, physical systems and their representation. Specifically, the most cogent proposals land in effective empirical underdetermination and mutual empirical equivalence, reviving old anti−realist fears about quantum physics. In this paper such fears are discussed and found unsound. It is argued that nothing of global skeptical or agnostic significance really follows from the kind of underdetermination presently encountered in fundamental quantum theory. The case is instructive, however, for what it shows about the characteristics and prospects of scientific realism as a perspective in contemporary philosophy of science.

Quantum ontology without speculation

“…By looking at some other parts of TQM, this section seeks to give further substance to the idea of a non-speculative quantum ontology and to dispel some objections raised by Callender ( 2020 , sec. 4.5) against Cordero’s ( 2001 ) version of realism about TQM. After setting aside examples that, although mentioned in some QM textbooks, are not truly quantum mechanical (such as basic claims about the shape and structure of the water molecule), Callender discusses three classes of phenomena to which a realist about TQM may want to commit himself ontologically: semi-classical orbits (e.g., in the hydrogen atom), quantum tunneling, two-path interference.…”

“…The answer is clearly negative in the case of Hoefer (2020), who essentially excludes the entire class of distinctively quantum theoretical claims from realist (and, consequently, representationalist) treatment. By contrast, Cordero (2001) and Saatsi (2019Saatsi ( , 2020 recognize the impressive empirical success of QM as a strong motivation for some kind of representationalism in the quantum domain, but the ontological payoff of their approaches remains unclear. As we will see in Section 4, Saatsi dissociates the representational role of quantum notions from what he calls truth-content realism by denying that we are able to identify the referents of these notions in a non-speculative way.…”

“…Another way to describe this predicament is to say that the choice between different quantum ontologies is underdetermined by the scientific evidence (Cordero 2001 ; Lyre 2010 ; Lewis 2016 , ch. 3).…”

Mitos y mentiras sobre el realismo científico

“…Por ejemplo, allí donde una teoría exhibe contenidos indiferentes a las pruebas experimentales disponibles (subdeterminación empírica "efectiva") resulta arbitrario tomar una posición realista en favor de dichos contenidos. Una situación así ocurre, por ejemplo, con la teoría de muchos mundos y la teoría GRW en la física cuántica (Cordero, 2001), donde dichas teorías describen mundos muy diferentes entre sí pero cuyas diferencias no son accesibles mediante la tecnología disponible. De lo que se trata, por consiguiente, es de identificar con cuidado las partes creíbles de una teoría exitosa.…”

Science and its Discontents: Is There an End to Knowing?

“…In support of their argument, anti‐realists refer to numerous theories in the past that fitted well with empirical data but have ultimately proven to be false (e.g., the theory of flat Earth, the theory that placed Earth in the center of our planetary system or the ether theory of light). They also point to the phenomenon of underdetermination (i.e., the existence of different and often conflicting theories that are supported by the same empirical evidence) as a proof that a fit is no guarantee of the validity of a theory (on underdetermination, see Hoefer and Rosenberg, ; Leplin, ; Bergström, ; Cordero, ; Belousek, ).…”