Self-organizing systems are systems in which lasting structures spontaneously appear as time goes on. Self-organization is a phenomenon common to biology, economics, sociology and many other fields in addition to chemistry. Within chemistry it is particularly associated with the so-called Brussels school, which has developed around Nobel laureate chemist Ilya Prigogine (b. 1917). Self-organization is also called autopoiesis, from the corresponding expression in Greek.

Self-organization is amply apparent in the biological world. Highly complex multi-cellular organisms develop from single cells. New species evolve to fill new ecological niches, and organisms living in the same ecosystem exchange matter and chemical energy in complex patterns. In contrast, isolated chemical systems tend towards equilibrium states which are homogeneous and unchanging. This observation has led some philosophers to claim that the organizing tendency apparent in living systems is evidence for a vital force, operating outside the realm of physics and chemistry...