Christian Universalists assert that the doctrine of eternal Hell was not a part of Christ's teachings nor even the early church, and that it was added in.[16] The first clear mention of endless misery is to be found in a work from 155-165 CE by Tatian.[17] Other early references to a Hell of infinite duration come from Latin church father Tertullian in the late 2nd and 3rd century.[18] According to Theologian Edward Beecher in the first four centuries there were six main theological schools and only one of them advocated the idea of eternal Hell.[19]