Each great change pushed people to think the thoughts the age needed.
It is certainly true that not all cultures are equally responsive to changing circumstances. The Islamic lands, for instance, have produced notoriously few democracies, Nobel Prize–winning scientists, or diversified modern economies. Some non-Muslims conclude that Islam must be a benighted creed, miring millions in superstition.
Culture and free will speed up or slow down our reactions to changing circumstances. They deflect and muddy any simple theory. But—as the story that filled Chapters 1–10 shows all too clearly—culture and free will never trump biology, sociology, and geography for long.
If China had escaped Jurchen and Mongol devastation, its renaissance culture might have blossomed into a scientific revolution instead of withering into complacency and footbinding. Internal demand from a hundred million Chinese subjects, trade between an agricultural south and an industrial north, and colonization in Southeast Asia might then have been enough to tip the balance. On the other hand, possibly not; until it had the kinds of guns and armies that could close the steppes, China remained open to devastating migrations.
Only in Asimov’s feverish imagination, they maintain, could knowing what has already happened tell you what is going to happen. Many historians deny that there are any big patterns to find in the past, while those who do think there may be such patterns nevertheless tend to feel that detecting them is beyond our powers.
I have tried to show in this book that historians are selling themselves short. We do not have to limit ourselves to the two hundred generations in which people have been writing documents. If we widen our perspective to encompass archaeology, genetics, and linguistics—the kinds of evidence that dominated my first few chapters—we get a whole lot more history. Enough, in fact, to take us back five hundred generations. From such a big chunk of time, I have argued, we really can extract some patterns; and now, like Seldon, I want to suggest that once we do this we really can use the past to foresee the future.
I suggested that we might well ask the same about Figure 12.1, which shows that if Eastern and Western social development keep on rising at the same speed as in the twentieth century, the East will regain the lead in 2103. But since the pace at which social development has been rising has actually been accelerating since the seventeenth century, Figure 12.1 is really a conservative estimate; the graph might be best interpreted as saying that 2103 is probably the latest point at which the Western age will end.
We all have free will, and, as I have repeatedly stressed, our choices do change the world. It is just that most of our choices do not change the world very much.
Evolution selects for what we call common sense.
An extraordinary number of modern inventions were made more than once, and the statistician Stephen Stigler even proposed a law that no discovery is ever named after its real discoverer.