Historians since Thucydides[1] have described how the rise and fall of civilizations, the victories and defeats of campaigning armies, have been shaped by changing patterns of disease[2]. Interactions among humans, other living creatures, plants, animals, micro organisms, ecosystems, and climate, geography, and topography are so complex that despite much study we are often uncertain what is really happening. Medical science supports the historians, but theories can mislead us if they try to explain complex historical events with inadequate supporting empirical evidence[3]. Life, the universe, and everything in it, are a crazy mixture of orderly with random, haphazard, chaotic processes that may defy rational analysis and explanation.