A keen student of theology, August Friedrich Gfrörer (1803–61) became professor of history at the University of Freiburg and also sat as a representative in the Frankfurt parliament, agitating for the reunification of Protestantism and Catholicism. His academic work marked the modern period in the Christian study of Judaism, making full use of primary sources without pursuing an obvious apologetic or polemical agenda. This two-volume work, published in 1831, is a critical study of early Christianity and the influence that Judaism had on the New Testament. Volume 2 is devoted to substantiating the thesis that the core principles of Philo's theology were already discernible among the Alexandrian Jews. Gfrörer traces how Philo's theology and philosophy were transplanted to Palestine via such sects as the Therapeutae and the Essenes as well as through the historian Josephus. The Apocrypha serve as Gfrörer's main primary source.