complex vs. complicated

from David Depew and Bruce Weber:

"Complex systems are not just complicated systems. A snowflake is complicated but the rules for generating it are simple. The structure of a snowflake, moreover, persists unchanged and crystalline, from the first moment of its existence until it melts, while complex systems change over time. It is true that a turbulent river rushing through the narrow channel of rapids changes over time too, but it changes chaotically. The kind of change characteristic of complex systems lies somewhere between the pure order of crystalline snowflakes and the disorder of chaotic or turbulent flow. So identified, complex systems are systems that have a large number of components that can interact simultaneously in a sufficiently rich number of parallel ways so that the system shows spontaneous self-organization and produces global emergent structures." (142)

qtd. in Mark C. Taylor, The Moment of Complexity (2001)