Written in 2002, this brief paper was presented to a small group in the Australian Defence Department which was interested in systems thinking as a way of solving major social problems.

It is an essay on some of the intellectual challenges designers face when they go about defining the boundary of any system they are thinking of redesigning. It is a compilation of ideas and case histories which I have used in other publications. Here I present them as a group specifically addressing some of the issues we face trying to fix or change the boundaries of the problems we try to solve.