ABSTRACT
Complexity is a seductive concept, and not just for economists. The view of the world provided by the physics that inaugurated the scientific revolution-with classical dynamics’ notion of a deterministic world governed by timeless laws, in which there is no reason in principle why the motion of a physical system could not be viewed the same backward as well as forward, so that all change is reversible-seems now one more vestige of a distant, much more rigidly structured, age. Laplace’s demon, who, given Newton’s laws and a description of the position and momentum of each particle in the universe, could predict and retrodict every event in the history of the universe, has been replaced by the famed butterfly of the lore of the popular literature on chaos theory, whose wings flapping can make the difference between a hurricane occurring or not occurring. After chaos theory demonstrated the extreme brittleness which characterizes many causal processes, the question of how order is possible (despite the chaos one finds in the universe) was bound to come to the forefront, with investigators searching for general principles for how this “order out of chaos” might come about. Corresponding to this shift there has been a rise in the prestige of biology relative to that of physics, helped along by the ubiquity and seemingly endless potential of the digital computer, which allows one to think of life as consisting of nothing so mundane and inelegant as gooey liquids, but as being produced at bottom by computer programs written in the genetic code.
