2. The evangelist Matthew has commenced his narrative in these terms: |The book of the generation of Jesus Christ, the son of David, the son of Abraham.| By this exordium he shows with sufficient clearness that his undertaking is to give an account of the generation of Christ according to the flesh. For, according to this, Christ is the Son of man, -- a title which He also gives very frequently to Himself, thereby commending to our notice what in His compassion He has condescended to be on our behalf. For that heavenly and eternal generation, in virtue of which He is the only-begotten Son of God, before every creature, because all things were made by Him, is so ineffable, that it is of it that the word of the prophet must be understood when he says, |Who shall declare His generation?| Matthew therefore traces out the human generation of Christ, mentioning His ancestors from Abraham downwards, and carrying them on to Joseph the husband of Mary, of whom Jesus was born. For it was not held allowable to consider him dissociated from the married estate which was entered into with Mary, on the ground that she gave birth to Christ, not as the wedded wife of Joseph, but as a virgin. For by this example an illustrious recommendation is made to faithful married persons of the principle, that even when by common consent they maintain their continence, the relation can still remain, and can still be called one of wedlock, inasmuch as, although there is no connection between the sexes of the body, there is the keeping of the affections of the mind; particularly so for this reason, that in their case we see how the birth of a son was a possibility apart from anything of that carnal intercourse which is to be practised with the purpose of the procreation of children only. Moreover, the mere fact that he had not begotten Him by act of his own, was no sufficient reason why Joseph should not be called the father of Christ; for indeed he could be in all propriety the father of one whom he had not begotten by his own wife, but had adopted from some other person.
3. Christ, it is true, was also supposed to be the son of Joseph in another way, as if He had been born simply of that man's seed. But this supposition was entertained by persons whose notice the virginity of Mary escaped. For Luke says: |And Jesus Himself began to be about thirty years of age, being (as was supposed) the son of Joseph.| This Luke, however, instead of naming Mary His only parent, had not the slightest hesitation in also speaking of both parties as His parents, when he says: |And the boy grew and waxed strong, filled with wisdom, and the grace of God was in Him: and His parents went to Jerusalem every year at the feast of the passover.| But lest any one may fancy that by the |parents| here are rather to be understood the blood relations of Mary along with the mother herself, what shall be said to that preceding word of the same Luke, namely, |And His father and mother marvelled at those things which were spoken of Him|? Since, then, he also makes the statement that Christ was born, not in consequence of Joseph's connection with the mother, but simply of Mary the virgin, how can he call him His father, unless it be that we are to understand him to have been truly the husband of Mary, without the intercourse of the flesh indeed, but in virtue of the real union of marriage; and thus also to have been in a much closer relation the father of Christ, in so far as He was born of his wife, than would have been the case had He been only adopted from some other party? And this makes it clear that the clause,|as was supposed,| is inserted with a view to those who are of opinion that He was begotten by Joseph in the same way as other men are begotten.