In concept a feedback system is a closed system. Its dynamic behavior arises within its internal structure. Any action which is essential to the behavior of the mode being investigated must be included inside the system boundary.

— Jay Wright Forrester, Principles of Systems (1968)

Source: http://obssr.od.nih.gov/issh/2012/files/Richardson%202011.pdf

Cited in Richardson (2011), who quotes Forrester's Principles of Systems (1968).

Topics: complexity