Critical Systems Thinking and the Management of Complexity

7 Complexity Theory

But it is nevertheless incumbent upon us to push the scientific paradigm as far as possible to determine where the boundaries are and not be deterred by the specter of overwhelming complexity and diversity

(West 2017, loc. 4658)

7.1 Introduction

It has been convincingly argued by Gleick (1987) that “chaos theory,” the forerunner of “complexity theory,” is one of the three landmark achievements of twentieth‐century science (see Section 2.3). There were, however, two earlier scientific discoveries that set the scene for the emergence of chaos theory. The first was due to Poincaré (1854–1912) and has frequently led to him being declared the founding father of chaos and complexity theory. The mathematician Poincaré was seeking to solve the so‐called “many‐body” problem in celestial mechanics. Newton's laws were fine for predicting the behavior of two bodies exerting gravitational forces on one another, but it was extremely difficult to extend them even to three bodies subject to mutual attraction. Poincaré did not completely succeed in providing a solution but he thoroughly grasped the nature of the problem he was up against:

But even if it were the case that the natural laws had no longer any secret for us, we could still only know the initial situation approximately. If that enabled us to predict the succeeding situation with the same approximation, that is all we require, and we should say that the phenomenon has been predicted, that it is governed ...