The balancing of private interests has hitherto been seen as the primary task of private law. Alexander Hellgardt shows in his post-doctoral dissertation, recently published by Mohr Siebeck, that private law is better conceived of as a tool which the legislator may use to regulate economy or society. Hellgardt illustrates the regulatory function of private law using sales law and property law as main examples. He examines regulation by means of private law in order to pursue public interest goals and presents conclusions for jurisprudence, legislation and legal practice.