Acknowledgment A lifetime of teaching and consulting involves indebtedness to innumerable sources of wisdom. I have learned from my students and clients far more than I ever taught them. Looking back, I can hardly even begin to recall the fires by which I was warmed, the lights by which I found my way. And yet there are faces that vividly stand out. Russel L. Ackoff has been my mentor, business partner, and a great friend. He was there, as always, with his infinite wisdom and uncompro- mising critique to examine every line and dissect every concept of this manuscript. I welcomed his measured views and took all of his recommendations. Reza Niazmand was the first who found my strange way of thinking interesting enough to trust me to convert The Industrial Management Institute, the entity he had spent all of his professional life to create, into a consulting research and training firm based on systems thinking. Unyielding support of this giant man during my exciting years of tenure as the head of the Industrial Management Institute set the stage for