Human societies each constitute a form of equilibrium. Equilibria are liable to catastrophes when, under special limiting conditions, small inputs may produce very large, often unforeseen, and frequently irreversible outputs. Analysts are hindered by the inadequacy of methodologies to deal with such discontinuities and random events and are usually obliged to make inappropriate assumptions that over a sufficiently long time span such discontinuities and surprises may be either ignored or will average out.
Surprises are by definition beyond the capacity of human capacity to predict. They may surprise as a whole, by the very nature of the events, or in crucial part, by their precise location and timing. Hitherto little known places become symbols for far-reaching actions and policies. Previously obscure individual emerge into prominence to shape human lives.