In this essay enquiry is made into the structural resemblances anddifferences between formal and substantive principles and whether the differences canbe explain Alexy’s «Law of Combination». After an outline of the distinction between rulesand principles the structural characteristics of formal principles are examined. The lastsection is devoted to the distinction of formal principles that are either independent ordependent on the balancing of other principles. It is argued that there are instances offormal principles that are not dependent on the balancing of other principles, and tothese cases the «Law of Combination» has no application.