The book deals with the practices and authorisations of legislation in the Middle Ages. Laws laid down norms, but they were also subject to norms. These were not only based on traditions, but also referred to goals that were to be achieved by means of new laws. One of these goals was the improvement of life. The associated willingness to innovate stood in contrast to the requirement to preserve the law. The contradictory development of both normative values, which characterised the evaluation of legislation, is examined.