Balancing is an indispensable instrument of legal reasoning, both with respect to the interpretation and application of basic and human rights and to numerous other fields of law. However, the objectivity, rationality, and legitimacy of this method are now being contested. It is criticised as irrational and arbitrary, a threat to legal certainty, and an illegitimate interference of courts with the political sphere. The contributions in this volume are devoted to an examination of these issues. Some of them discuss the structure of balancing and offer advanced theoretical analyses. A main focus is Robert Alexy's "weight formula". Other issues are the problem of rationality of balancing and its legitimacy in judicial decision-making, in particular regarding the application of the principle of proportionality in constitutional and European Community law.