📒 Otto Pfleiderer (1839-1908) was a German Protestant theologian, known as one of the most influential representatives of liberal theology. Volume IV of Primitive Christianity covers the Gospel of John, Johannine Theology, the origin of the Johannine writings, the "Catholic writings of an Edifying Character," the Celementine writings, early Apologetic writings, and the theology of the Apologists, plus an index to all four volumes and errata.