Bohm's approach and individuality
2 : Department of Philosophy, University of Helsinki
1 : School of Humanities and Informatics, University of Skovde
3 : Theoretical Physics Research Unit, Birkbeck College, University of London
When discussing identity and individuality in quantum mechanics, Ladyman and Ross (2007) suggest that quantum particles are not individuals (or, at most, are weakly discernible individuals). They acknowledge that there is a version of quantum theory, namely the Bohm theory, according to which particles do have definite trajectories at all times. However, they then interpret the work of Brown et al. (1996) as implying that the properties normally associated with particles (mass, charge, etc.) are inherent only in the quantum field and not in the particles. They conclude that haecceities seem to be needed for the individuality of particles of the Bohm theory. We note that Brown et al. elsewhere (1999) suggest that in the Bohm theory properties such as mass and charge also reside in the particles. If so, the individuality of particles in quantum theory is a genuinely open question, more so than Ladyman and Ross imply. Bohm and Hiley were also engaged with a broader “implicate order” scheme which goes beyond the Bohm theory. We discuss some relevant similarities this framework has to Ladyman and Ross's ontic structural realism. We will also discuss how individuality can be understood in the implicate order scheme.
