Inspired by this question, I have a more general one: What is, historically speaking, a civilization?
We can identify broad traits that make a society a civilization- agriculture, city building, social structures, etc. But what separates one civilization from another, both geopolitically and chronologically? Is there a widely accepted definition of "a civilization" that identifies a particular time period or region as being one distinct from others? What factors would be considered in defining a specific civilization?
For example, why would (not) the Roman Republic and the Byzantine Empire be considered the same civilization? What about the Byzantine Empire and the Western Roman Empire?