Exchanging quantum particles

Tomasz Bigaj

pp. 185-198

in: Gerhard Heinzmann, Pierre É. Bour, Wilfrid Hodges, Peter Schroeder-Heister (eds), Logic and philosophy of science in Nancy (II), Philosophia Scientiae 19 (1), 2015.

Abstract

The mathematical notion of a permutation of indices in the state description admits different physical interpretations. Two main interpretations analyzed in this paper are: exchange of essences and exchange of haecceities. It is argued that adopting the essentialist approach leads to the conclusion, contrary to the conventional wisdom, that quantum particles of the same type are sometimes discernible by their properties. The indiscernibility thesis can be supported only by the alternative interpretation in terms of primitive thisness.