Calculations on Conversion

Jody recently sent me an article from the science blog Gene Expression entitled ” Historical Dynamics and contingent conditions of religion.” Basically, what the piece argues is that the same types of mathematical formulas that Peter Turchin uses to explain the rise and fall of states can also be used to predict the rise and fall of religions. It is an interesting idea, and his article, while long and rather complex, is certainly worth a read:

Mathematically oriented works are pretty straightforward and you can reject it or accept it (or not understand it). In any case, I want to focus on another issue which is emphasized in Historical Dynamics , the autocatalytic model of religious conversion. The idea here is simple; the rate of conversion is proportional to the number of converts, and the result is a logistic curve over time. Turchin draws strongly upon Rodney Stark & co’s work on the importance of transmission through social networks, and uses textual data to suggest that the growth of Christianity during the Roman Empire, and Islam in both Spain and Iran, seem to map well onto a logistic growth function.

. . .

It seems that autocatalytic process will result in Africa becoming totally Muslim or Christian. On the other hand, if it takes 1,000 years for India and China to become totally Christian or Muslim . . . well, I’m not sure if that certain projection is really that useful seeing as how 1,000 years is a long enough time that a lot of the background parameters could change. Additionally, there are various frequency dependent dynamics and mixed morphs which are likely operative in these historical social trajectories that I think are being left out in this treatment.

Did you get that? I think the upshot of the whole thing is that mathematical calculations can be useful when trying to evaluate and predict historical trends, even the trends of conversion. The author of the article, however, did a good job emphasizing that this approach to history shouldn’t be understood as an exact science, but rather a tool that can help break down and process extremely complex events. As far as I’m concerned, it’s a good example of how different academic disciplines can interact with and inform each other.

The danger, of course, is that an overly confident mathematical approach to history could produce a new form of historical determinism. Individual human agency, as well as the mysterious agency of the Holy Spirit, would be circumscribed, which, in the end, would be a history hardly worth reading.