  What is a systems approach? The first step towards answering this question is
an understanding of the history of the systems movement, which includes a
survey of contemporary systems discourse. In particular, I examine how systems
researchers differentiated their contribution from mechanistic science - but
also from holistic doctrines; and identify the similarities and sharpest
differences between complex systems and other systems approaches. Having set
the scene, the second step involves developing a definition of 'system'
consistent with the spirit of the systems approach.
