I am a realist about the existence of individuated natural systems in the world, of which we humans are instances. I also believe that we, as well as all natural systems, are embedded in a larger world-network which shares the same underlying character. So how do I address the ancient problem of how the many could arise from the one?
The classical view of a world comprised of uniform fundamental particles of stuff following simple deterministic laws cannot solve the problem. Large systems in nature gain and lose these particles through time, but retain a nature which seems to transcend them.
If you adopt an event or process ontology, this challenge becomes easier. An event unfolds: it is a becoming. This means a possibility becomes actualized. It then changes the space of possibilities available for the next event. To make this work you do have to violate the purity of monism, but only slightly. The nodes of the network include an ability to actualize and also be actualized. This is a duality, but not a pernicious one. It seems to be the minimum complication necessary to create a chain or network of events. Otherwise there is no change (and therefore really no reality). Whitehead and his intellectual heirs are the most prominent advocates of a view with these ingredients historically.
For a very recent example of how this kind of system can work comes from Gregg Rosenberg. In Chapter 9 and subsequent chapters his book, A Place for Consciousness (which I have discussed previously here and here), he lays out a detailed metaphysical proposal of causality and the structure of what he calls “natural individuals”. To do the work of causation he postulates that there exist two kinds of (interdependent) properties, effective properties and receptive ones. Effective properties have a range of possible values, while receptive properties are needed to place the effective properties and determine them. Then Rosenberg makes one more key move which is to say the receptive property is connective in nature (one receptive field can bind more than one effective property). This allows complexes of effective properties to be bound together at multiple levels of nature (not just the micro-level) to form natural individuals.
The breathtaking ambition of this metaphysical proposal is such that it not only explains causality and the formation of individuals, but the receptive property is seen as that which gives rise to experience for the system, thus forming the basis of a theory of consciousness.
But for now, what I take away from these ideas is that the process of actualizing possibilities can explain the causal structure of nature, and this foundation provides enough richness to create a model which explains the presence of individuated natural systems within the larger world-network.
To finish this post, I want to revisit what I see as the strong compatibility of this metaphysical structure with quantum mechanics. In a measurement of something like an electron, position, charge or spin are the effective properties. The "ability to measure" (or ability to receive information) of the measuring system is the receptive property. The one thing missing from quantum theory is how larger natural systems which have this ability to measure are put together.
But perhaps physicists working on decoherence theory will figure this out. I am intrigued by the work being done here, but am severely limited in my ability to understand the papers (I hope I can find some work by a good philosopher of physics to help me out). Some interesting quotes have stuck in my head from this paper by Wojech H. Zurek (whose work was briefly discussed in this post). After summarizing the progress made in his theory, which among other things involves regarding observers as “open quantum systems, distinguished only by their ability to acquire, store and process information”, he says in his conclusion that “Many conceptual and technical issues (such as what constitutes ‘a system’) are still open.” I speculate that, consistent with Rosenberg’s theory, the “ability to acquire information” also includes a connective property which allows “open quantum systems” to form.