This book has argued that social structures have causal powers and sought to explain how this can be the case. This concluding chapter will summarise the argument, draw out its implications for the question of naturalism and discuss some of the issues that need to be addressed in further work.

The causal power of social structures

The claim that social structures have causal powers depends on a realist philosophical ontology of causal powers as relationally emergent properties of things (discussed in chapters 2 and 3). In this ontology, the world in which we live is understood to be populated by entities, or things, each of which is in turn composed of other such entities. At one level down from the entity we find a set of its parts, but each of these is also an entity composed of parts and this hierarchical structure continues all the way down to the most fundamental components of our world, whatever they may be. The concept of emergence is essential to our understanding of these structures and their causal powers because it enables us to see how the entities at each level can have causal powers of their own, despite being in a sense ‘nothing more’ than a collection of lower-level parts.

Relational emergence theory argues that entities may possess emergent properties, which are produced by mechanisms that in turn depend on the properties of the entity's parts and how those parts are organised.