Idacius or Idathius
Idacius or Idathius surnamed CLARUS, a Spanish prelate, was born in the first half of the 4th century. After his accession to the bishopric of Emerida he distinguished himself by the intemperate zeal with which, together with Ithacius (q.v.), bishop of Ossonoba, he opposed the heresy of Priscillian (q.v.). He wrote a refutation of the latter's doctrine under the title Apologeticus, which is now lost. In 388, after the death of the emperor Maximus, who had persecuted the Priscillianists, Idacius resigned his bishopric. Having subsequently attempted to regain it, he was exiled, and died about the year 392. According to Sulpitius Severus, Idacius's conduct was less severely judged by his contemporaries than that of Ithacius. The writings ascribed to him are given in the Bibliotheca Patrum, vol. 5. See Sulpitius Severus, Historia Sacra; Isidore of Seville, De Scriptoribus Ecclesiasticis; Antonio, Bibl. Hispana vetus, 1, 172; Hoefer, Nouv. Biogr. Géneralé, 29:775; Neander, Ch. Hist. 2, 111 sq.; Kurtz, Ch. Hist. 1, 214 sq. SEE PRISCILLIANISTS.