The life of Bar Daisan, of which some particulars have been preserved for us by Bar Hebraeus and other Eastern historians of the Church, throws considerable light upon the attitude towards Christianity of Valentinus and that Anatolic School which best represented his teachings. Bar Daisan was born some fifty years after Valentinus of rich and noble parents in the town of Edessa in Mesopotamia, where he seems to have been educated in the company of the future king of the country, Abgar Bar Manu[421]. He was probably a Christian from his infancy, early became a Christian teacher, and withstood Apollonius, a Pagan Sophist who visited Edessa in the train of the Emperor Caracalla, making avowal of his readiness to suffer martyrdom for the faith. According to Eusebius, he had the greatest abhorrence of the dualistic doctrine of Marcion and wrote books against him in his native Syriac which were afterwards translated into Greek[422]. He, or perhaps his son Harmonius[423], also composed a great number of hymns which were sung in the Catholic Churches of Mesopotamia and Syria; and it was not until a century and a half after his death that Ephrem Syrus, a doctor of the now triumphant and persecuting Church, found that these abounded in the errors of Valentinus, and deemed it necessary to substitute for them hymns of his own composition[424]. Valentinus seems in like manner to have lived in Rome as a Christian teacher, as we have seen, for at least sixteen years, and to have composed many psalms, some of which are quoted by Clement of Alexandria. If Tertullian is to be believed, he was qualified for the episcopate, which he must have had some chance of obtaining; and his want of orthodoxy cannot, therefore, have been manifest at the time or considered an objection to his candidature[425]. Moreover, Irenaeus says that Valentinus was the first who converted the so-called Gnostic heresy into the peculiar characteristics of his own school[426]; which agrees with Tertullian’s statement that Valentinus was “at first a believer in the teaching of the Catholic Church in the Church of Rome under the episcopate of the Blessed Eleutherus[427].” It is evident, therefore, that long after his peculiar teaching was developed, he remained a member of the Church, and that it was not by his own wish that he left it, if indeed he ever did so.