[UPDATE: 25 Sept.2009: Links fixed, but note the post refers to an earlier draft of the paper]
As a follow-up to the last post, I want to very briefly take note of Jonathan Schaffer’s noble attempt to argue that the fundamental (ontologically prior) level is the whole rather than the parts – “priority monism”.
The draft paper “Monism: the Priority of the Whole” includes a fairly lengthy discussion of a historical context in which the case for monism has mostly gone unappreciated (it is often caricatured and dismissed as the position that there exists exactly one thing). He takes some time explicating the idea that both the whole and the parts exist, one of these must be prior, and the choice of either the whole or the parts is an exclusive and exhaustive list of options. Then it is “game on” to see which prevails.
There are four sections to the argument over priority. Two of these I consider a tie: the argument over which comports best with common sense, and which option better explains the apparent heterogeneity of the world (he’s right to say that saying pluralism explains heterogeneity begs the question).
The next section asks what fits best with science. Here, I think Schaffer makes a mistake. He invokes the idea of entanglement from quantum mechanics and infers that the whole world is entangled, making reference to a wave function for the entire universe. In my opinion, this is wrong. The entire world would be entangled only from a perspective standing outside the universe. There is no wave function for the entire universe. The interactions (measurements) between the many quantum systems in the world constitute concrete reality, and the whole of the concrete world is the relational network of these many interactions.
The last section asks which view on priority best deals with the possibility of the world being made of “gunk”, which is stuff with no proper parts (or to put it another way, stuff which is infinitely divisible). Schaffer references a couple of scientific theories and speculations that physical entities might be infinitely divisible. Here I think the existence of the Planck scale is actually good evidence of a limit to divisibility, so again his attempt to invoke science doesn't succeed.
I think that if we’re speaking of our concrete world, then the parts are prior to the whole. The possibility is open, however, that there is a holistic non-concrete ground of possibilia which supports the parts, but this would be a different discussion.