The problem with civilization is that you need an agreed upon definition.

-- Does it depend on population size (2? 2 million?)?
--Certain style of living (migratory, stable, agrarian...)?
--Certain attributes (eg, infrastructure)?
--Does it depend on a certain level of self-awareness (how many animals live in schools, pods, herds, etc ... why are they not civilized?)?
--development of a certain set of behaviors/cultures/traditions?

I don't think it's necessarily "artificial," as it seems to be a byproduct of people associating with each other. Past a critical size, people realize the need to cooperate, maintain order, etc, and a group mentality emerges. And since most people tend to want attention, one wonders if any given couple could constitute it's own civilization.