I am sometimes a little confused by systems thinking discussions. By definition, a system comprising two or more parts working together to accomplish common purpose, Is it not? I am not sure I understand the idea that structure determines behavior. From my physiology background, I know structure constrains or limits behavior. The idea of feedback loops is clear enough in that since systems are driven toward their purpose, they have devices or sensors that collect intelligence and feed them back to the system for corrective action. In various parts of our body are receptors that pick up thermal, chemical, pressure signals that are sent to appropriate centers for evaluation against thresholds. When there is need, these centers send out signals to appropriate parts of the system for action. Is this systems thinking or what?