Involuntarily airborne dog explains complexity

In a recent discussion on the marvelous Knowledge Management for Development email list, Ueli Scheuermeier recounted this great explanation of the difference between complicated and complex, which he had first heard from Irving Borwick:

“If you put a football on the penalty point and then have a guy kick it towards the goal, that is a complicated process whereby through the application of knowledge of physics etc. you can actually predict the trajectory of the football. But there are many variables that make it a rather complicated data-collection and calculation. But it’s still complicated not complex.
If, however, you put a dog there on the penalty point and a guy comes along and kicks it, you can never predict what will happen next. All you know is the general environment and the framework in which something will happen, but what exactly will happen you don’t know. That’s complexity. It usually comes up when living people (in this case an animal) and their decisions and reactions are involved and influence an outcome. When humans are involved, outcomes are never predictable. That’s complexity”.