In Defence of Processual Structuralism in Biology

Ontic Structural Realism, or Structuralism, has been criticized for not being extendable to the special sciences. In this PhD thesis, I defend a biology-based structuralism by reconciling it with processualism, resulting in what I term ‘processual structuralism.’ I argue that there are three motivations within biology for supporting structuralism in this domain. Recent years have seen the emergence of two prominent schools in the philosophy of biology: new mechanism (e.g., MDC 2000; Glennan 1996, 2010, 2011, 2017; Illari and Williamson 2013; Kaiser and Krickel 2017; Krickel 2018) and processualism (Dupré and Nicholson, 2018; Dupré, 2021b). While both are inspired by scientific practices and have received significant attention, they present contradictory views on the ontology of biology: the former is based on object ontology, whereas the latter focuses on dynamic processes. In this thesis, I demonstrate the incompatibility of object-based metaphysics of mechanisms with the prevailing trends in the philosophy of physics by addressing the so-called bottoming-out problem, which I argue motivates a structuralist metaphysics of mechanisms. Furthermore, I discuss how processualism faces challenges from dispositionalism, particularly its inability to accommodate the metaphysics of biological causation without objects possessing dispositional powers. I also present the challenge that processualism faces in maintaining a realist stance distinct from instrumentalism. I argue that all these issues can be resolved through my processual structuralism, in which I propose that the metaphysical underpinnings of mechanisms are structures, which are understood as processes with inherent causal power. I elaborate on their metaphysical nature by comparing them with existing metaphysical theories of mechanisms. In the final chapter, I show how my account provides a metaphysical framework for interventionism regrading causation.