Caleb Hazelwood (et al.), “The Unbearable Lightness of Intervening”
Channel: CEFISES at UCLouvain
Date: 2023-08-08

Talk given at the Mechanisms and Ontic Causation in the Life Sciences conference, the second workshop of the MeCauLife group.

(work with Yasmin Haddad)

Abstract (abbreviated): According to an interventionist account of causation, X causes Y when a manipulation in X triggers a manipulation in Y. This account is especially fruitful in the context of scientific practice (e.g., experimental biology). However, interventionism is often considered to be an ontologically light account of causation on the grounds that it avoids metaphysical commitments. Some view this agnostic approach to metaphysics as a strength of interventionist accounts, whereas others view it as a weakness. The principal strength of an ontologically light account of interventionism is that it can be applied with ease to many practical cases, regardless of any outstanding metaphysical problems or metaphysical disagreements among researchers. For example, Woodward (2014) argues that interventionism is a functional account of causation that is best understood in terms of the goals of a causal explanation. As a result, interventionist accounts are context-specific and easily transposed to empirical settings. On the other hand, critics of interventionism highlight that it is ontologically light to a fault: it avoids metaphysical pitfalls by avoiding metaphysics, and therefore fails to tell us about the true nature of causation.

We argue that, on this particular issue, both the proponents and the critics of interventionism base their claims on a misleading assumption. The ambiguity is not in their appraisal of interventionism's metaphysical agnosticism. It comes much sooner than that: with their assumption that interventionism is an ontologically light account in the first place. Contrary to these claims, we argue that interventionism is—ontologically speaking—actually quite rich. Even though interventionism is argued to be a functional account of causation, there is no reason why Woodward's functional account should not be compatible with (or perhaps even ground) a metaphysical account of causation.

We rely on insights from discussions of “practice-centered” and “perspectival” realism to develop an ontology for interventionism. We have recent work by Hasok Chang (2022) and Michela Massimi (2022) especially in mind. Massimi, for instance, advocates for an “epistemology-first” approach to realism, rather than traditional “metaphysics-first approaches that engage in reading essential properties...off our current best theories” (2022, p. 15). For Massimi, we reach the “real” via our epistemic access to phenomena. Similarly, Chang argues that, while “scientific practices are surely not infallible guides to philosophizing,” they “provide as good a starting point as any in epistemology, with clear implications for metaphysics, too” (2022, p. 120). At the core of Chang's “realism for realistic people” is the notion of “operational coherence,” i.e., “aim-oriented coordination in an activity, a matter of doing what makes sense to do” (p. 121). Operational coherence thus gives rise to Chang's “coherence theory of reality,” according to which “an entity is real to the extent that there are operationally coherent activities that can be performed by relying significantly on its existence and properties” (ibid.).

We argue that the causes picked out by interventionism are accommodated by Chang's coherence theory of reality. Such an account allows us to reconcile the practical utility of interventionism with otherwise “heavy” commitments to metaphysical realism. We assume it is uncontroversial to say that many scientific practices (e.g., models, explanations, experiments, etc.) depend on or invoke the kinds of causal relationships that are identified by interventionism. Woodward's functional account helps us reliably identify such relationships—relationships that are as much informed by our epistemic aims as they are by a “mind-independent” world. In the company of perspectival and practice-centered realists, we submit that an account such as Chang's coherence theory of reality is as ontologically rich as an empirically minded philosopher can reasonably expect. Finally, we demonstrate the force of this argument with a well-known and widely debated case: interlevel causation.