Yihan Jiang

Recently, Jiang (2024; 2025a) has proposed a novel processual structuralist framework that integrates structuralism (ontic structural realism) with processualism for the metaphysics of biology. In this paper, I further develop the account and shows how it sheds new light on key debates within structuralism and the metaphysics of causation, advancing current discussions in these areas. In particular, I focus on two further implications of this framework: First, drawing inspiration from certain new mechanists (e.g., Illari and Williamson 2013; Krickel 2018), I argue that the framework naturally gives rise to an activity-based account of causation within structuralism, thereby addressing a gap in the literature on structuralism and causation in the special sciences. Although some scholars have explored the relationship between structuralism and causation, particularly in the Special Topical Collection of Synthese (Hüttemann 2017), few have specifically addressed how structuralism might accommodate causation within the special sciences. Here, I show how this novel structuralist account of causation advances beyond previous attempts, such as those by Ladyman and Ross (2007) and French (2014). Furthermore, I argue that this activity-based account of causation offers a novel metaphysical foundation for the interventionist account, filling in another previously underexplored limitation in the existing literature. Interventionism, while widely adopted in the philosophy of science, has often been criticized for its lack of explicit metaphysical grounding (e.g., Kuorikoski 2014). By grounding causation in the activities and processes characterized within a structuralist framework, the account offers the ontological basis that interventionism requires. In doing so, it contributes to the broader philosophical task of furnishing a robust metaphysical framework for interventionism.

In recent years, the philosophy of biology has undergone a significant shift known as the ‘processual turn,’ largely influenced by the works of John Dupré and his collaborators (Dupré, 2013, 2020; Nicholson and Dupré, 2018; Nicholson, 2019). Processualism argues that dynamic processes, rather than static objects, form the fundamental ontology of biological reality. This perspective, however, appears to be in tension with scientific realism, at least in its standard form, which is committed to the existence of discrete, mind- independent entities as posited in scientific theories. To reconcile these perspectives, I propose that effective realism, particularly the framework based on the real pattern account (Ladyman and Ross 2007; Wallace 2010), offers a promising solution. According to this account, real patterns are defined by their utility—they are patterns that are indispensable for formulating useful generalizations, enabling us to explain and predict phenomena efficiently. These patterns are objective features of the world, but their recognition depends on the stance or perspective we adopt, which is shaped by our explanatory purposes and cognitive tools. By understanding biological objects as patterns of processes—stable, emergent features within the dynamic flux of underlying processes—we can maintain a (minimal) realist commitment to the entities posited by scientific theories without abandoning the processualist ontology. Drawing on the real pattern account, I argue that interpreting objects as patterns of processes resolves the tension between processualism and scientific realism, affirming the reality of biological objects while preserving the primacy of processes. Meanwhile, this paper extends the application of the real patterns framework by demonstrating its utility in addressing specific challenges in the philosophy of biology. In doing so, it highlights how this Dennettian legacy continues to profoundly enhance our understanding of the fundamental reality revealed by the sciences.

Recent years have witnessed the rise of two schools in the philosophy of biology: new mechanism and processualism. Both frameworks are deeply rooted in scientific practices and have generated extensive scholarly discussion. However, they hold fundamentally opposing views on the ontology of biology: new mechanism is grounded in an object-oriented ontology, while processualism emphasizes dynamic processes. Given their profound influence in philosophy of biology, reconciling these schools while clarifying their distinct ontological commitments has become a critical challenge. This article proposes a monist solution to this problem specifically advocating for processual monism. I argue that processu- alism constitutes the only fundamental ontology and that the metaphysical commitments of mechanism can be appropriately accommodated within this framework. The central aim of this article is to address a key obstacle in defending processual monism: how processualism can account for the metaphysics of causal relations associated with mechanisms. In mechanistic explanations, entities are linked by causal relationships and many philosophers contend that causal power in biology originates from the disposi- tions intrinsically possessed by biological objects. Since processualism rejects the existence of such objects, its capacity to provide a coherent metaphysical account of causation has been called into ques- tion. In response, I argue that processualism can ground causation without appealing to the dispositions of objects by drawing on metaphysical tools from structuralism. This synthesis results in what I term ‘processual structuralism’. On this account, processes are understood as inherently causal and serving as the truth-makers of causal relations, consistent with the insights of structuralism. This approach al- lows processualism to accommodate the causality captured by mechanistic statements while retaining its core ontological commitments.

Existing metaphysical accounts of mechanisms commit to the existence of objects or entities posited in scientific theories, and thus fall within the category of maximal metaphysics. In this paper, I demonstrate the incompatibility of object-based metaphysics of mechanisms with the prevailing trend in the philosophy of physics by discussing the so-called bottoming-out problem. In response, I propose and flesh out a structuralist metaphysics of mechanisms based on Ontic Structural Realism (OSR), which is a kind of minimal metaphysics. I argue that the metaphysical underpinnings of mechanisms are structures, whose metaphysical nature is elaborated through comparison with existing metaphysical theories of mechanisms. After that, I address the concern of whether objects in mechanisms can be accommodated in my account by invoking existing metaphysical theories of objects in special science by structuralists, such as Ladyman, J., & Ross, D. ( 2007 ). _Every Thing Must Go: Metaphysics Naturalized_. Oxford University Press.)’s real pattern account, and suggesting a potential alignment between OSR and processual ontology. Finally, I demonstrate how my view can naturally serve as the metaphysics for Mechanism 2.0 and be applied to systems biology.