Chapter II.—Catechetical Instruction. § 1.  Catechesis.  The term “Catechesis” in its widest sense includes instruction by word xx of mouth on any subject sacred or profane73, but is especially applied to Christian teaching, whether of an elementary kind appropriate to new converts, or, as in the famous Catechet- ical School of Alexandria, extending to the higher interpretation of Holy Scripture, and the exposition of Christian philosophy. The earliest known example of a Catechetical work is the “Teaching of the Twelve Apostles,” which Athanasius names among the “books not included in the Canon, but ap- pointed by the Fathers to be read by those who are just recently coming to us, and wish to be instructed in the word of godliness (κατηχεῖσθαι τὸν τῆς εὐσεβείας λόγον)74.”  The use of the Didache for the instruction of recent converts from Paganism agrees with its original purpose as stated in the longer title, “Teaching of the Lord through the Twelve Apostles for the Gentiles.”  The first six chapters are evidently adapted for those who need elementary instruction, more particularly for Catechumens of Gentile descent, as distinct from Jewish candidates for Baptism75.  The remaining chapters of the Didache relate chiefly to the ad- ministration of Baptism, to Prayer, Fasting, and the services of the Lord’s Day, and to the celebration of the Agape and Eucharist76.  This same division of subjects is observed in the two classes of S. Cyril’s Catechetical Lectures:  the first class, including the Procatechesis, consists of XIX Lectures addressed to candidates for Baptism, and these are followed by five “Mystagogic” Lectures, so called as being explanations of the Sacramental Mysteries to the newly-baptized. The Didaché was taken as the basis of other manuals of instruction, as is evident from the fact that the greater part of the first six chapters is imbedded in “ The Apostolical Church Order,” supposed to date from Egypt in the third century.  The Greek text, with an English translation, of the part corresponding with the Didaché, is given in “ The oldest Church Manual “ as Document V. A further development of the Didaché, “adapted to the state of the Eastern Church in the first half of the fourth century,” is contained in the Seventh Book of the Apostolical Constitutions of Pseudo-Clement of Rome, chs. i.–xxxii.  “Here the Didaché is embodied almost word for word, but with significant omissions, alterations, and additions, which betray 73 Acts xviii. 25; xxi. 21, 24; Rom. ii. 18; Gal. vi. 6.  Cf. Clem. Alex. Fragm. § 28:  οὐκ ἔστι πιστεῦσαι ἄνευ κατηχήσεως. 74 Festal Epist. 39.  Compare Clem. Alex. Strom. V. c. x. § 67.  Γάλα μὲν ἡ κατήχησις οἱονεὶ πρώτη ψυχῆς τροφὴ νοηθήσεται. 75 Schaff, Oldest Church Manual, p. 15. 76 Ib. p. 26. Catechetical Instruction. 20 Catechetical Instruction.