I have a new paper out (open access), called “Turning Salmon’s causal theory into process ontology.” In it, I provide a modified account of causal process theory. It is intended to meet the aims of biology-inspired philosophers who advocate for a process-oriented metaphysics, while maintaining a close tie to the topic of scientific explanation. In this post, I talk a bit about the ideas in the paper, while giving some of the background for how I came to write it.
The paper’s launching point is its engagement with a 2021 article from John Dupré, but its roots go back to my (2018) dissertation. There I presented a unified account of causal explanation in the natural sciences, with some applications. The challenge to such a project, of course, is that there is incredible variety in the forms that explanations can take across physics, chemistry and biology. These explanations deploy many types of models to represent phenomena (the target systems). But thinking about the practice of modeling is helpful for tackling the challenge of unification. Models feature idealizations, and (as contemporary theorists have emphasized) while these can often be characterized as abstractions from detail, they are more than this: they play a positive representational role that is tailored to help audiences grasp explanations. And since idealized models cannot not be taken as true depictions of phenomena, one shouldn’t assume that the disparate forms of model-based explanation indicate that the natural world they represent is itself fragmented (or “dappled”). The goal is to find the common thread in how model-based explanations of worldly phenomena work.
Because successful scientific explanations are (mostly or entirely) causal, their various elements must represent causal features of the targets. So, this is where one must look for the common thread. Here I turned to Wesley Salmon’s work (dating to the 70’s and 80’s), which I had long admired. His approach to scientific explanation posited that phenomena were explained by fitting them into the world’s causal structure, which he described as a web or network of interacting “causal processes”. For various reasons (reviewed at length in the dissertation and briefly recounted in the paper), this effort failed. One reason was that it wasn’t clear he could account for the full variety of explanations. But another problem is that it fell short as a theory of causation: this was unsurprising given Salmon’s desire to avoid metaphysical commitments. I updated and modified Salmon’s theory to create the unified causal/ontological backdrop to explanation that I sought. Two main moves were to endow Salmon’s processes with dispositions/causal powers, and to also introduce an account of composition, allowing for processes at various scales. Finally, I argued that causal elements of even highly idealized explanatory models can be seen as standing in for features of the web of interacting powerful processes.
After graduating, I did not pursue an academic career, and for this (and other reasons) I never submitted the core of this work for publication. Then, in 2021, Dupré published the article (mentioned above) that shared key elements of my perspective: first, that an approach to causation like Salmon’s could have much broader application than generally thought, and second, that using the metaphysics of causal powers could be a good fit for the framework (this paper was included in a special issue of Synthese dedicated to the work of G.E.M. Anscombe). Dupré came at these ideas from a bit different direction: he (along with other philosophers) had been arguing that the distinctive characteristics of biological phenomena pointed toward the need for a process-oriented metaphysics, although the details of what this should look like remained to be filled in. Notably, the turn to considering Salmon-style accounts suggested that, in addition to providing a theory of causation, they could also provide the right kind of ontological picture for process advocates.
When I saw the Dupré paper, I briefly regretted not getting my own work published earlier but then realized it was obviously an exciting development that he had landed on similar views. It was thus a good spur to write an article: I still had an original contribution to make by fleshing out the ideas further, including on the topic of how the process picture connects to scientific explanation from physics to biology. After some further delays (including 22 months under review!), the paper is finally out. It covers a fair amount of ground and necessarily engages only briefly with a number of controversial topics that deserve more attention: there are clearly many targets for objections! I hope folks give it a read.