some heretics, he evidently understood the genealogical tables, though, in relation to the Ebionites, he might likewise have included under this expression the history of the birth. How is the strange phenomenon, that these genealogies are not found among that very sect of Christians who retained the particular opinion upon which they were constructed, to be explained? A modern investigator has advanced the supposition, that the Jewish-christians omitted the genealogical tables from prudential motives, in order not to facilitate or augment the persecution which, under Domitian, and perhaps even earlier, threatened the family of David. [237] But explanations, having no inherent connexion with the subject, derived from circumstances in themselves of doubtful historical validity, are admissible only as a last refuge, when no possible solution of the questionable phenomenon is to be found in the thing itself, as here in the principles of the Ebionitish system. But in this case the matter is by no means so difficult. It is known that the Fathers speak of two classes of Ebionites, of which the one, besides strenuously maintaining the obligation of the Mosaic law, held Jesus to be the naturally begotten Son of Joseph and Mary; the other, from that time called also Nazarenes, admitted with the orthodox church the conception by the Holy Ghost. [238] But besides this distinction there existed yet another. The most ancient ecclesiastic writers, Justin Martyr and Irenæus for example, are acquainted with those Ebionites only, who regarded Jesus as a naturally born man first endowed with divine powers at his baptism. [239] In Epiphanius and the Clementine Homilies, on the other hand, we meet with Ebionites who had imbibed an element of speculative Gnosticism. This tendency, which according to Epiphanius is to be dated from one Elxai, has been ascribed to Essenic influence, [240] and traces of the same have been discovered in the heresies referred to in the Epistle to the Colossians; whereas the first class of Ebionites evidently proceeded from common Judaism. Which form of opinion was the earlier and which the later developed is not so easily determined; with reference to the last detailed difference, it might seem, since the speculative Ebionites are mentioned first by the Clementines and Epiphanius, whilst Ebionites holding a simpler view are spoken of by Justin and by Irenæus, that the latter were the earlier; nevertheless as Tertullian already notices in his time the Gnosticising tendency of the opinions of the Ebionites respecting Christ [241], and as the germ of such views existed among the Essenes in the time of Jesus, the more probable assumption is, that both opinions arose side by side about the same period. [242] As little can it be proved with regard to the other difference, that the views concerning Christ held by the Nazarenes became first, at a later period, lowered to those of the Ebionites