Ecclesiastical Chronicle, Volume 1

Severus; Xenaias.

Severus of Antioch and Philoxenus, or Xenaias of Mabug, treading a path almost midway between Eutychianism and the true faith of the Council of Chalcedon, devised a method of defending their heresy that was much more subtle and very apt for deceiving the incautious or the less learned. They taught, namely, that the divinity and humanity were united in Christ without change and without confusion—in which they seemed to approach the orthodox—but then, immediately deviating from the right faith, they asserted that after the union there were not two natures in Christ, but one composite nature (ܚܕܐ ܟܝܢܐ ܡܪܟܒܐ), or one double nature (ܚܕܐ ܟܝܢܐ ܥܦܝܦܐ).

These expressions, like the badge of the Jacobites, either have no meaning or necessarily involve the very confusion of natures which they profess to reject. They tenaciously clung to these, however, wrongly abusing certain words of the Holy Fathers, and especially of Cyril of Alexandria, in whose writings—as they were written before the Council of Chalcedon—the terms nature (φύσις, ܟܝܢܐ) and subsistence (ὑπόστασις, ܩܢܘܡܐ) were not so rigorously defined to a single sense. Hence Cyril, although he clearly preaches two natures in Christ without division, without change, and without confusion, nevertheless speaks more than once of the "one incarnate nature of the Word," using the term nature for a subsisting nature or hypostasis. The Jacobites, however, understanding this and similar formulas of speech perversely, have lost, or at least have confused, the true notion of the terms nature (ܟܝܢܐ) and hypostasis (ܩܢܘܡܐ), which—miraculously—they still hold correctly when they deal with the mystery of the Holy Trinity. This can be affirmed regarding several of their principal teachers, particularly Philoxenus and Barhebræus. "Philoxenus, in his treatise on the incarnation," as St. J. Assemanus observes1, "acts as neither an orthodox nor a Eutychian, but treads a certain middle path, which the Jacobites after him held and hold to this very day: namely, that there is one nature in Christ, composed of divinity and humanity."

1: Biblioth. Orient., II, 25.