[7] The conception underlies the whole of Tertullian’s treatise, _de Baptismo_: it accounts for the rites of exorcism and benediction of both the oil and the water which are found in the older Latin service-books, e.g. in what is known as the Gelasian Sacramentary, i. 73 (in Muratori, _Liturgia Romana vetus_, vol. i. p. 594), “exaudi nos omnipotens Deus et _in hujus aquæ substantiam immitte virtutem_ ut abluendus per eam et sanitatem simul et vitam mereatur æternam.” This prayer is immediately followed by an address to the water, “exorcizo te creatura aquæ per Deum vivum ... adjuro te per Jesum Christum filium ejus unicum dominum nostrum ut efficiaris in eo qui in te baptizandus erit fons aquæ salientis in vitam æternam, regenerans eum Deo Patri et Filio et Spiritui Sancto....” So in the Gallican Sacramentary published by Mabillon (_de Liturgia Gallicana libri tres_, p. 362), “exorcizo te fons aquæ perennis per Deum sanctum et Deum verum qui te in principio ab arida separavit et in quatuor fluminibus terram rigore præcepit: sis aqua sancta, aqua benedicta, _abluens sordes et dimittens peccata_....” [8] These conceptions are found in Xenophon’s account of Socrates, who quotes more than once the Delphic oracle, ἥ τε γὰρ Πυθία νόμῳ πόλεως ἀναιρεῖ ποιοῦντας εὐσεβῶς ἂν ποιεῖν, Xen. _Mem._ 1. 3. 1, and again 4. 3. 16: in Epictet. _Ench._ 31, σπένδειν δὲ καὶ θύειν καὶ ἀπάρχεσθαι κατὰ τὰ πάτρια ἑκάστοις προσήκει: repeatedly in Plutarch, e.g. _de Defect. Orac._ 12, p. 416, _de Comm. Notit._ 31. 1, p. 1074: in the _Aureum Carmen_ of the later Pythagoreans, ἀθανάτους μὲν πρῶτα θεούς νόμῳ ὡς διάκεινται, τίμα (_Frag. Philos. Græc._ i. p. 193): and in the Neoplatonist Porphyry (_ad Marcell._ 18, p. 286, ed. Nauck), οὗτος γὰρ μέγιστος καρπὸς εὐσεβείας τιμᾶν τὸ θεῖον κατὰ τὰ πάτρια. The intellectual opponents of Christianity laid stress upon its desertion of the ancestral religion; e.g. Cæcilius in Minucius Felix, _Octav._ 5, “quanto venerabilius ac melius....majorum excipere disciplinam, religiones traditas colere;” and Celsus in Origen, _c. Cels._ 5. 25, 35; 8. 57. [9] The following is designed to be a short account, not of all the elements of later Greek education, but only of its more prominent and important features: nothing has been said of those elements of the ἐγκύκλιος παιδεία which constituted the mediæval _quadrivium_. The works bearing on the subject will be found enumerated in K. F. Hermann, _Lehrbuch der griechischen Antiquitäten_, Bd. iv. p. 302, 3te aufl. ed. Blumner: the most important of them is Grasberger, _Erziehung und Unterricht im classischen Alterthum_, Bd. i. and ii. Würzburg, 1864: the shortest and most useful for an ordinary reader is Ussing, _Erziehung und Jugendunterricht bei den Griechen und Römern_, Berlin, 1885. [10] _Litteratura_ is the Latin for γραμματική: Quintil. 2. 1. 4. [11] _Adv. Gramm._ 1. 44.