Firmianus Lactantius, one of the fathers of the Latin church, born, according to some, in Firmium, Italy, according to others, in Africa, about 260, died in Treves about 325. The names Lucius Ccelius or Caecilius, sometimes bestowed on him, are not mentioned by Jerome and Augustine, or found in any ancient manuscript. According to his own account, he was born of heathen parents, and became a Christian at a mature age. Jerome calls him a pupil of the African Arnobius, under whom he studied rhetoric at Sicca, near Carthage. In early life he published in hexameters a work entitled Symposion, being a collection of riddles for convivial amusement. This work gained him such a reputation that he was invited by Diocletian in 301 to open a school of eloquence in Nicomedia, where he remained till 312. As this city was almost exclusively inhabited or visited by Greeks, Lactantius found but few pupils. During his stay there the Christians were persecuted, and their religion assailed by the heathen philosophers. Having, it is surmised, become himself a Christian about this epoch, he wrote in defence of the persecuted creed his great work Institu-tiones Divince, of which, while still in Nicomedia, he composed an epitome addressed to his brother Pentadius. This was followed by another entitled De Opificio Dei. In the former work Lactantius proposes to demonstrate the right of the Christian religion to exist legally, and to communicate its doctrines by public teaching; in the latter he grounds the belief in the existence of a God on the adaptations seen in every known form of organic life.

In 312 Lactantius was called to Treves by the emperor Constantino, to superintend the education of his son Crispus. He appears to have lived in great poverty while in Nicomedia, and to have distinguished himself by his modesty and disinterestedness while at court. Before his conversion to Christianity, Lactantius had been a diligent student of the great Roman orator, whose harmonious and eloquent style he had labored so successfully to imitate that he acquired from posterity the appellation of the " Christian Cicero," and St. Jerome says that he was by far the most learned man of his age. Besides the works mentioned, he wrote a treatise De Ira Dei, which is still extant, two books to Asclepiades, and eight books of letters, which are lost. The work De Mortibus Persecutorum is thought by many of the best critics to belong to Lactantius, and to be identical with the work De Persecutione Liber unus mentioned as his by St. Jerome. The first edition of his works was printed at Subi-aco in 1465; later editions are by Le Brun and Lenglet du Fresnoy (2 vols. 4to, Paris, 1748), Pere Edouard de St. Francois Xavier (14 vols. 8vo, Rome, 1754-'9, considered the best), and in Gersdorf's Bibliotheca Patrum Ecclesice se-lecta (vols, x., xi., Leipsic, 1842). - See "A Summary of the Writings of Lactantius," by the Rev. J. H. B. Mountain (London, 1839).