 Bauer likened the present crisis to the end of the classical world in Roman imperialism. His studies in the 1850s located the origins of Christianity in the second century CE, concluding that the first gospel was written under Hadrian (117–138 CE), though slightly predated by some of the Pauline epistles. Bauer traced the evolution of Christian ideas from Hellenism and Stoicism, deriving the logos doctrine of John’s gospel from Philo and neo-Platonic sources. As in Herr Dr. Hengstenberg, he denied that Christianity had emerged directly from Judaism. More than in his early work, though, he now stressed the revolutionary power of the early Christian religion, as a source of liberation for the excluded and impoverished elements of the Roman Empire. His final book described Christianity as the socialist culmination of Greek and Roman history. Responding to this argument in his very positive obituary of Bauer, Friedrich Engels acknowledged the importance of Bauer’s late work for the socialist critique of religion (Sozialdemokrat, 1882). In 1908, Karl Kautsky’s book, The Origins of Christianity, applied Bauer’s thesis.