While in Phrygia, however, he continued to govern his diocese, as well as writing two of the most important of his contributions to dogmatic and polemical theology: the "De synodis" or "De fide Orientalium", an epistle addressed in 358 to the Semi-Arian bishops in Gaul, Germania and Britain, analyzing the views of the Eastern bishops on the Nicene controversy. In reviewing the professions of faith of the Oriental bishops in the Councils of Ancyra, Antioch, and Sirmium, he sought to show that sometimes the difference between certain doctrines and orthodox beliefs was rather in the words than in the ideas, which led to his counseling the bishops of the West to be more reserved in their condemnation.