The reasons why it has always been difficult for me to seriously believe in the one-world-huge-all-in-government conspiracy theory are multiple:
1) game theory leads us to think exactly the opposite because power is a finite and contestable resource;
2) human sociobiology leads us to think exactly the opposite because we are an intrinsically competitive, expansionist and traitorous species;
3) the history of civilizations leads us to think exactly the opposite;
4) an omnivalent conspiracy theory is not scientifically falsifiable, nor are the majority of the hypotheses put forward by its supporters;
5) last, but most important of all: those who really believe it have never participated in a condominium meeting.
Men unite and divide at all levels of power. This means that cooperative/conspiratorial and competitive/conflictual processes coexist at all levels. Why should they behave differently at the top than at the bottom if the biology is the same? And even if, paradoxically, it wasn't the same: perhaps the "gods" of the ancient texts didn't slaughter each other?
