I have found the model of punctuated equilibrium to be the most convincing analogy/model for historical change.  During my undergraduate work I conducted research for the Honors History program which revolved around the writings of Bernard of Clairvaux (a 12th century French monk).  That essay began with research on the topic of the Peace of God Movement, which predated the First Crusade by about a century.  Reading through the Peace of God movement, the First and the Second Crusade (which Bernard preached) and the early years of the Military Order of the Poor Knights of Christ (the Templars) seemed another example of this punctuated equilibrium.  Society was developing along a line, with dead-ends, fits and starts, that had at its core ideas about masculinity, religion, and warfare.  There were moments, such as the Peace of God movement or the formation of the Military Orders, that jumped the entire process ‘forward’ – they were too novel to be seen as simply the next small step in a cultural chain, but they were clearly not absent from the ideas that came before.

The arguments about the nature, and especially the timing, of the Revolution in Military Affairs (RMA) provides another interesting example of this.  Argument for the location of the RMA range from the nineteenth back to the fourteenth century – once you’ve read the argument that a ‘revolution’ which resulted in what we had in the 20th century began six hundred years earlier it becomes hard to see it as a revolution and much easier to see it as a process.  That process was certainly not constant, and those moments that are usually picked out for particular argument as the ‘one’ temporal location of the RMA seem to be more the moment of punctuation within the gradual flow of change.

This model allows for both the influence of history, culture, tradition, and learning on human development, but it also allows for the impact of imagination, genius, and congruence of circumstance.