Abstract
The essays in the first part, Approaches to Ontology, explore different philosophical frameworks in which the ontology of QFT could fruitfully be examined. Despite their differences, they all agree that traditional ontologies, in particular substance-attribute ontology, are unsuitable for QFT. Peter Simons begins by pointing out why substance-attribute ontology, applied set theory, fact ontology, occurrent ontologies, and trope theory are inadequate ontologies for QFT and then puts forward his own suggestion: factored ontology. The main idea of this ontology is to posit basic features (so-called ‘factors’) and to view objects as suitable combinations of some of these factors. He presents an outline of a version of a factored ontology, called PACIS, which he and his collaborators have developed over the last fifteen years and which they have – in their view successfully – applied to different domains in the natural and the social sciences. Given this success, Simons is confident that this framework will also prove fruitful in the case of QFT. However, he does not give any further argument for this claim and does not make an attempt at formulating a concrete factor 1 ontology of QFT. He merely puts forward his framework as a conceptual tool and leaves it to the philosopher of physics to work out an interpretation of QFT in its terms.