According to the science of cybernetics, which deals with the topic of control in every kind of system (mechanical, electronic,biological, human, economic, and so on), there is a natural law that governs the capacity of a control system to work. It says that the control must be capable of generating as much "variety" as the situation to be controlled.

Anthony Stafford Beer
Another Quote

10 Common Mistakes That Prevent You From Being Happy and Healthy Today, Backed by Science