Woodcut of the monastery and the city of Sankt Gallen

1. Gratian began teaching canon law by using the case law method  (The Christopher Columbus Langdell of Bologna).  Gratian was the first jurist to use this methodology for an entire work. 3. With the expansion of the Decretum in subsequent recensions Gratian attempted  to make his work a comprehensive source of canonical sources.
2. He began teaching canon law in the early twelfth century as Adam Vetulani and Stephan Kuttner noted "Ur-Gratian could go back much further than the 1130s.  His purpose: Teaching, teaching, teaching.

4. Gratian's "hypothetical" remained an important element of law school education through  the literary genre of  "Questiones" which evolved in the thirteenth century.