In the late 60s, Gilles Deleuze began to formulate some of the philosophical significances of what is now sometimes referred to as “chaos/complexity theory,” the study of “open” matter/energy systems which move from simple to complex patterning and from complex to simple patterning. Though not a term used by contemporary scientists in everyday work, it can be a useful term for a collection of studies of phenomena whose complexity is such that Laplacean determinism no longer holds beyond a limited time and space scale. Thus the formula of chaos/complexity might be “short-term predictability, long-term unpredicability.” (I leave it at “predictable,” an epistemological term, because people get nervous with “indeterminate,” an ontological term. Thus we’re only talking epistemology, or at best heuristic ontology.)
The groundbreaking works in identifying Deleuze’s (and Deleuze & Guattari’s) interest in this field are Brian Massumi’s A User’s Guide to Capitalism and Schizophrenia and Manuel De Landa’s “Non-organic Life” in Incorporations: Zone 6. Although post-modern appropriations of science–to say nothing of critiques–have been the focus of much negative attention lately, due to the notorious Sokal hoax, there does seem to be good cause to take seriously the work of Deleuze and Deleuze & Guattari.