  Dietrich’s scientific treatises are famous. His treatises on light (De luce), on color (De coloribus), and on the rainbow (De iride) contributed greatly to the development of optics and were composed in the scientific spirit of Albertus Magnus. Fr. William A. Wallace in his The Scientific Methodology of Theodoric of Freiberg, one of the few studies of Dietrich in English, demonstrates the dependence of Dietrich’s scientific methodology on his philosophical theories, and particularly his logical writings. This dependence reveals the Albertist tendency in Dietrich, leaving no doubt that in some way he was influenced by the writings and spirit of Albert the Great.