SERAPIONE, bishop of THMUIS, saint. — In the Syriac Calendar a S. is recorded on 19 March; from there he passed into the Hieronymian Martyrology on the 21st of the same month; Eusebius mentions him (Hist. eccl., VI, 41, 8). In the ninth century, Florus of Lyon, followed subsequently by Ado, identified him with S. of Thmuis. The Roman Martyrology depends on the aforementioned interpolators.
S., at first a catechist in Alexandria, probably at the Didascaleion, withdrew into the desert of Amun, became abbot of a monastic colony, and formed a close friendship with s. Antonio Abate and with s. Atanasio. If the letter of Atanasio in which an S. is mentioned refers to our subject (PG 26, 1412 ff.), it must be supposed that S. was already bishop of Thmuis in Lower Egypt before 339. He was a learned man and, in all likelihood, took part in the Council of Sardica (343) as a supporter of his friend Atanasio and of the Council of Nicea against the Arians; for the same reason he was sent to the imperial court of Costanzo II (c. 356); he seems to have died after 362. The title of “confessor” bestowed on him by s. Girolamo (PL 23,699) he appears to have deserved through the exile imposed on him by the Arian Ptolemy after the Council of Sardica.
Very little remains of S.’s theological production. Known under his name is a treatise against the Manichaeans (G. Bardy, La question des langues dans l'Eglise ancienne, Parigi 1948, p. 42), which, however, like the other works of the period, was no more than a collection of general information, external to the sect (cf. H.-Ch. Puech, Le Manichéisme, son fondateur, sa doctrine, Parigi 1949, pp. 15-26); its arguments against the dualistic principle and the origin of evil are nevertheless good. S.’s Trinitarian doctrine is among the simplest. The consubstantiality between the Father and the Son is designated by the imprecise term “omoios” instead of “omousios”; his Christological terminology is likewise no more precise. This does not compromise his orthodoxy but rather represents the mode of expression of a bishop governed more by pastoral than by polemical concerns. Indeed, if he was sent to the Council of Sardica, if s. Atanasio believed that he could address writings to him
on the Holy Spirit (PG 26, 529-676), and if he had initially been a catechist in Alexandria, it would follow that he was capable of treating theological problems with a better regard for the requirements of theological terminology. Indeed, according to others, s. Atanasio held his friend’s learning in such high esteem that he submitted his manuscripts to him for examination.
An Euchologion, or collection of 30 prayers, is attributed to S., but it cannot yet be critically established whether he was its author or merely its compiler: this Euchologion seems to contain prayers considerably earlier than S. The first is an anaphora of particular theological as well as liturgical interest (P. Batifol, Etudes d'histoire et de théologie positive, 3ª series: L'Eucharistie, 7ª ed., Parigi 1920, pp. 311-34).