§ 2.  Authenticity of the Lectures.  The internal evidence of the time and place at which the Lectures were delivered has been already discussed in chapters viii. and ix., and proves beyond doubt that they must have been composed at Jerusalem in the middle of the fourth century.  At that date Cyril was the only person living in Jerusalem who is mentioned by the Ecclesiastical Historians as an author of Catechetical Lectures:  and S. Jerome, a younger contemporary of Cyril, expressly mentions the Lectures which Cyril had written in his youth.  In fact their authenticity seems never to have been doubted before the seventeenth century, when it was attacked with more zeal than success by two French Protestant Theologians of strongly Calvinistic opinions, Andrew Rivet (Critic. Sacr. Lib. iii. cap. 8, Genev. 1640), and Edmund Aubertin (De Sacramento Eucharistiæ, Lib. ii. p. 422, Ed. Davent., 1654).  Their objections, which were reprinted at full length by Milles at the end of his Edition, were directed chiefly against the Mystagogic Lectures, and rested on dogmatic rather than on critical grounds.  The argument most worthy of notice was that in a MS. of the Library of Augsburg the Mystagogic Lectures were attributed to John, Bishop of Jerusalem.  This is admitted by Milles, who gives the title thus:  Μυσταγωγικαὶ κατηχήσεις πέντε ᾽Ιωάννου ᾽Επισκόπου ῾Ιεροσολύμων, περὶ βαπτίσματος, χρίσματος, σώματος, καὶ αἵματος Χριστοῦ.