Spencer and Realism
Spencer distinguished nominalism (society is nothing more than the sum of its elements) from realism (society is a distinct and separable entity). Spencer advocated realism due to the “permanence of the relationships between component pieces that produce the uniqueness of a whole.”
People continually see society as an entity because, although being composed of discrete units, the pervasiveness of their interrelationships across the inhabited area implies a certain concreteness in the aggregate of these units. So, Spencer thought of society as a “thing,” but it wasn’t like any other thing except for how its parts are put together, which follows similar rules.