More on Causation and Reduction to Physics

I finished reading GettingCauses from Powers by Stephen Mumford and Rani Lill Anjum.  I recommend the book highly to anyone interested in causation, and I’ll be thinking about many of its arguments and themes for a long time to come.

As touched on at the end of my prior post, one possible challenge to models of causation, including the thesis of causal dispositionalism presented in this book, is the fact that causation doesn’t seem to comport well with physics.   The authors acknowledge this in their first chapter, referencing Russell’s discussion in his "On the Notion of Cause” (1913).  The issue is that dynamical equations associate states of a system with points in time, but nowhere do they invoke the idea of causal production.  They are symmetric with regard to time, where causation is not.  Mumford and Anjum respond in a couple of ways.  First, they say, the fact that causation doesn’t appear at the level of physics doesn’t mean it isn’t present at larger scales:  the reducibility of all phenomena to physics is a controversial idea which we are not compelled to accept.  We don’t know that physics represents a special fundamental level of reality in any case.  And given the provisional nature of scientific theories, should we let them trump our metaphysical reasoning?

This issue recurs as the book progresses.  In Chapter 4, the authors show how the composition of powers in causal situations can plausibly model emergent phenomena in the form of novel powers.  So the theory is robust if it does turn out that reduction of the phenomena in the special sciences isn’t possible.  And the final chapter of the book (ch.10) presents an interesting and persuasive application of the theory by showing how causal dispositionalism fits quite well with examples of processes studied in biology (including genetics).

Just like the situation in philosophy of mind, one must be cautious about drawing metaphysical conclusions from the perceived character of formal physical theory.