In effect, there seems to be no end to the emergence of emergents. Therefore, the unpredictability of emergents will always stay one step ahead of the ground won by prediction. . . . As a result, it seems that emergence is now here to stay.
-- J. Goldstein, Emergence as a Construct
One of the impulses behind science is the desire to gain reliable knowledge about the world so that we can control it. There is no denying the extraordinary success of this enterprise, which has given us electrical illumination, television, jet aircraft, antibiotics, computers, artificial pacemakers for the heart -- the list goes on. The principle that underlies these technologies is an orderly and predictable relationship between cause and effect. More often than not the relationship is linear: the illumination from the light bulb changes in direct proportion to the amount the dimmer switch is turned; the power from the jet engines varies directly with the movement of the throttle. But the linear relationship between cause and effect in such processes holds only over a limited range; it always fails if that range is exceeded.
Nonlinearity does not mean that control is not possible. Plenty of nonlinear processes are orderly, predictable, and hence controllable. The pendulum of a grandfather clock follows a well-defined, stable cycle of nonlinear motion. Small extraneous impulses to the pendulum