Complexity theory philosophy

Assemblage is a philosophical approach for studying the ontological diversity of agency, which means redistributing the capacity to act from an individual to a socio-material network of people, things, and narratives.
Also known as assemblage theory or assemblage thinking, this philosophical approach frames social complexity through fluidity, exchangeability, and their connectivity.
Its central thesis is that people do not act exclusively by themselves, and instead human action requires complex socio-material interdependencies.

A New Philosophy of Society: Assemblage Theory and Social Complexity is a 2006 book by the philosopher Manuel DeLanda.
The book is an attempt to loosely define a new ontology for use by social theorists — one that challenges the existing paradigm of meaningful social analyses being possible only on the level of either individuals (micro-reductionism) or society as a whole (macro-reductionism).
Instead, the book employs Gilles Deleuze's and Félix Guattari's theory of assemblages from A Thousand Plateaus (1980) to posit social entities on all scales that are best analysed through their components.