ABSTRACT
Keywords: Hierarchy Theory, Complexity, Scaling, Integrated Assessment, Non-equivalent descriptive domains, Post-Normal Science.
Acknowledgments
I would like to thank Matthias Lüdeke, Kozo Mayumi, Jerome Ravetz for their valuable comments to previous versions of this paper, as well as the participants of the Matrix workshop on Scaling Issues in Integrated Assess-ment for their useful comments to my presentation. Special thanks are also due to Frank Nelissen for his outstanding job of editing the original manuscript.
