During his career he held teaching posts at the universities of Berlin, Breslau, and Heidelberg. As a leading figure of the Germanist school of juristic thought, he challenged Friedrich Carl von Savigny's historical school and Bernhard Windscheid's dogmatic school, then dominant in Germany. The Germanist school proposed to study the development of German law from its earliest beginnings, with a view to creating a common basis for the new national legislation needed by a unified Germany. Three ideas dominated Gierke's thinking: 1) law comes from the people; 2) there is a uniquely German conception of law, independent of Roman law; and 3) Germanic law was not extinguished by the reception of Roman law in Germany.
Gierke had a remarkably clear eye for the social problems of his time. For example, he perceived the danger of absolute contractual freedom in those areas of life, such as the employer-employee relationships, in which the parties did not enjoy equality of bargaining power. His books stimulated greatly the sociological approach to law.