Are Elementary Particles Individuals? A Critical Appreciation of Steven French and Décio Krause’s Identity in Physics: A Historical, Philosophical, and Formal Analysis

Steven French and Décio Krause have written what bids fair to be, for years to come, the definitive philosophical treatment of the problem of the individuality of elementary particles in quantum mechanics and quantum field theory. The book begins with a long and dense argument for the view that elementary particles are most helpfully regarded as non-individuals, and it concludes with an earnest attempt to develop a formal apparatus for describing such non-individual entities better suited to the task than our customary set theory. Along the way one is treated to a compendious philosophical history of quantum statistics and a well-nigh exhaustive (I'm tempted to say, " exhausting ") analytical history of philosophical responses to the quantum theory's prima facie challenge to classical notions of particle individuality. The book is also a salvo from the headquarters artillery company of the " pro " side in the contemporary structuralism wars, and an essay in metaphysical naturalism. Whew! There are too many places where the friendly critic wants to engage the argument, and few where the authors have not already anticipated such engagement. I take this as my excuse, then, for offering not any systematic response to the whole project, but just some questions and observations about several points that caught my attention.