Most historians, and virtually everyone on the political left, views most human interactions as zero-sum (to borrow a term from game theory). One person's gain is another person's loss.
In fact, the potential for positive-sum interactions (where both people gain) exists always and everywhere there are human beings. Granted, there are impediments – oppressive governments, war, plaques, etc. But people will naturally and inevitably exploit opportunities for mutually beneficial exchange. They will also create markets, languages, the rule of law and other institutions that promote non-zero-sum outcomes.
Just as there is a natural and inevitable tendency for biological evolution to lead to increasingly more complex life forms, so there is a natural and inevitable tendency for human cultures to evolve to greater levels of economic and technical complexity. What determines the speed of this evolution? Two factors: (1) how fast new ideas arise and (2) how quickly they spread. The latter, in turn, is limited only by barriers to transportation and communication.
These insights help explain why large empires, such as the Roman Empire, had salutary effects on the people it governed:
- By eliminating small-scale wars in the provinces (Pax Romana), ancient Rome created an environment that allowed people over vast distances to exploit opportunities for gains from trade.
- And by building a vast network of roads ("all roads lead to Rome") the empire greatly lowered the costs of transportation and communication.
These insights also encourage us to rethink the benefits of the fall of Rome, most accounts of which were written by Romans themselves – who saw the Goths, Huns and Vandals, as "uncivilized". Granted, the "barbarians" didn't read Greek poetry or eat their salad with a salad fork. But their rule wasn't all bad.
- By the end of empire, Rome was stagnant and decaying because of a parasitic and oppressive government that stifled free enterprise and left much positive-sum potential untapped.
- The new barbarian rulers were better economic managers; not only did they not destroy intentionally the Roman economy, they replaced the Romans as tax collectors and otherwise left the peasants alone.
Non-Zero-sum thinking also casts a new light on the "dark ages" – which as it turns out, weren't so dark. Unencumbered by oppressive political rule and taking advantage of a reasonable amount of peace provided by the feudal system, people developed markets, invented new products (including the printing press) and exploited opportunities for positive-sum interactions.
Developments on the other side of the world during this time are also instructive.
- In the late 15th century, centralized rule in Japan was replaced by a Shogun feudal system similar to late Medieval Europe; as a result, towns expanded and markets flourished.
- By contrast, China during this period had centralized and oppressive rule and experienced cultural stagnation.