Common wisdom has it that civilization begins when a culture begins to have a consistent surplus of food.
A fine point, maybe even a good one. But I would put it a little differently.
Civilization begins when a culture develops a consistent and significant surplus of labor.
To explain my point. If you look at the few surviving hunter/gatherers, every or almost every member of the band has one purpose in life: Gathering food.
A slightly more sophisticated culture is likely to have two individuals exempt from such duties: The chief and the shaman or priest. These individuals are, in most cultures, selected from those less useful for gathering food. The chief is generally an old man or an old woman. The shaman, in many such cultures, is actually disabled...it's not uncommon for a deformed child or a young person crippled in an accident to be trained as a shaman...thus making them more useful (other cultures tended to select as the shaman an individual who was unlikely to reproduce by virtue of not conforming to norms of gender and sexuality...those of the 'third gender'...yet another way of making the shaman somebody less 'useful' in normal terms).
But then something happens. A woman realizes that if she puts the seeds of a favored plant closer to camp, she won't have to search for them. A man comes up with the concept of, instead of following the herds, getting the herds to stay put. People invent fences. The fence is a very important invention, up there with fire. Think about it. Where would we be without fences.
Somebody invents ploughing. Somebody else realizes that rather than pull this plough around himself, he'll train a horse or a cow to do it for him...much more efficient.
Every technological development in human history has held one purpose: Reducing the amount of direct labor a human must put to a task. Although we tend to hold a certain ideal of the 'great leisure time' of prehistoric man...just like any other animal, every 'wild' human has to worry about getting food.
Now. Answer this question.
How many farmers do you know?
I know precisely one (not counting, here, the stallholders at the farmer's market). And she's part time.
How many readers of this blog grow even a small portion of their own food? Sure, it's trendy of late to have a garden. But even if you do, if your crop fails, you...go to the supermarket and buy food.
You can't build pyramids if everyone is working the fields. You certainly can't have a government in the modern sense.
This trend has accelerated. In the 1890s, the percentage of the population of the United States involved in farming has been estimated as between 70 and 80 percent. In 2008? 2 to 3 percent. In fact, if you know somebody with Farmer as a surname? It doesn't mean what you think it means. When English surnames were 'settling' a farmer was a tax collector. You don't need a special word for somebody who works the land when ninety percent of your population is doing it...you only need special words for those who don't.
In short, as technological development increases, the amount of labor required to feed the population decreases.
As early agriculture became more efficient, farmers no longer needed all of their children to work the land. A surplus of labor was created. The chief slowly became the king, with sub kings under him. The shaman became the priest, then the high priest. Casual barter between individuals became organized trade.
No doubt, in that process, some people ended up in that limbo that we today call 'unemployment'...their labor was of no value. And with technology, the value of labor reduces.
So, today, we have jobs that no American citizen will take because the value of the labor is too low.
Historically, humanity has dealt with the value of labor dropping too low in two ways. One is to throw a war (which rapidly increases the value of labor). The other is to invent new uses for labor.
None of us want a war.
And there is, of course, a third way...to increase the value of labor by slowly reducing the number of human beings. We could simply try breeding less.
Most likely, though, we will need to create jobs in the most literal sense of the word...by inventing new ones.