FILASTRIUS OF BRESCIA. - Ecclesiastical writer of the 4th century, d. between 391 and 397. From the discourse delivered in his honor by his successor St. Gaudentius, on the 15th anniversary of his death (PL 20, 997-1002, CSEL 68, pp. 135-39), we learn that F., having left his homeland (which is not named), was ordained a presbyter and traveled as a pilgrim through almost the entire Roman world to preach the word of the Lord, fighting against the gentiles, Jews and heretics, especially against Arianism, and enduring corporal punishments for this as well. At Milan he opposed Auxentius, the Arian predecessor of Ambrose; he labored also for a long time at Rome; having then come to Brescia, he was elected its bishop, seventh in the series of pastors of the Church of Brescia: this not later than 381, in which year he subscribed, as bishop of Brescia, the acts of the Council of Aquileia. Even as bishop he was sometimes at Milan, with St. Ambrose, with whom St. Augustine saw him (Ep. 222, 2), between 384 and 387.
He composed a Liber de haerentibus, between 383 and 391, in which he enumerates 136 heresies, 28 Jewish and 128 Christian. The list of the latter is divided into two parts, of 64 chapters each: the first, more concise, gives the biography of heretics and heresiarchs; the second, modeling itself on doxographic collections, expands in the exposition of doctrines. The great number of heresies - almost double those enumerated by St. Epiphanius, who in his Huerser had listed 80 - grouped in an evidently artificial numerical schematism, is reached by means of repetitions and faulty duplications, counting among the heresies, both Jewish and Christian, also interpretations of biblical passages held to be erroneous by the author; who, as St. Augustine already noted (epist. cit.), did not have a clear concept of heresy. Augustine, who reproaches the same defect also in Epiphanius, nonetheless considers the latter superior to F. The latter, in truth, displays neither historical sense nor speculative aptitudes. The interesting part of his work is that which comprises the last 64 heresies (chaps. 93-156), where he seems to speak with direct knowledge. As for the rest, the sources have not yet been sufficiently studied. It was first thought that F. had drawn on the aforementioned work of Epiphanius; now the prevailing opinion is that the two used a common source, the Syntagma of Hippolytus. Although of scant value, the work of F. had a not despicable fortune, since St. Gaudentius, St. Augustine in the homonymous treatise and the so-called Predestinatus made use of it.