Post-Pridie (or the COLLECTIO POST MYSTERIUM or POST SECRETA, as it is called in the Gallican office) is the prayer of the Anaphorae (q.v.) of the Mozarabic liturgy. Various opinions are entertained regarding the belief of the Eastern Church on the doctrine of the Invocation of the Holy Ghost (q.v.) in the consecration of the elements. These opinions may be summarized in the following three:
(1) That the Eastern Church gives it no effect in the act of consecration, believing that to take place solely, entirely, and properly in the words of institution.
(2) That it believes both the words of institution and those of invocation to be coordinately efficacious to the same end.
(3) That the whole force of the consecration is vested in the invocation. (For the history of the controversy, see Neale, Introd. 1, 493 sq.) Neale, than whom there is no better authority on the subject, believes "that the sense of the Oriental Church may be thus expressed: The bread and wine offered on the altar are transmuted into the body and blood of Christ by the words of institution, and by the invocation of the Holy Ghost by the Church; and if either of these things be wanting, the Eucharist, so far forth as the orthodox Eastern Church is concerned, is not valid. I make the limitation because the Oriental Church has not condemned her Roman sister for the omission of the invocation" (Introd. 1, 496).
The Post-Pridie varies with the festival on which it is used. Thus, e.g, the prayer said on the first Sunday after apparition is as follows:
"Mindful, O Lord, of thy precepts, we earnestly pray thee that thou wouldst pour forth on these sacrifices the plenitude of thy Holy Ghost, that while we receive them blessed of thee, we may in all ways rejoice that we are filled with all manner of benediction, and are freed from the bonds of our sins. Amen. Through this gift, holy Lord, for thou createst all these things very good for us, thy unworthy servants, sanctifiest them, quickenest them, blessest them, and grantest to us that they may be blessed of thee, our God, to ages of ages. Amen." Cardinal Bona, who calls the belief of the Greeks a detestandus error, though he denies it to be more than an opinion held by some members of the Eastern Church, is rather baffled by the Mozarabic office. He tries to prove that it is only to be taken relatively to the receiver, and quotes the Mass for the first Sunday after Pentecost: "Be pleased to bless and sanctify to us the gifts," etc. By parity of reasoning it might be argued that the Roman Church only believes in a relative change, because the prayer in the canon runs, respecting the yet unconsecrated bread and wine, "that to us they may become the body and blood of Jesus Christ." The Post-Pridie in the Gotho-Hispanic rite seems always to have contained this invocation; but in the mutilation and changes to which that office has been subjected comparatively few masses have retained it in direct terms. The Post-Pridie for Easter-day, though not containing a direct invocation of the Holy Ghost, has a most remarkable prayer for change: "Ut hic tibi panis cum hoc calice oblatus in Filii tui Corpus et Sanguinem, te benedicente, ditescat." This may be profitably compared with the Ximenian Post-Pridlie for Corpus Christi; the difference is astonishing: "Ut panis hic transmutatus in Carnem, et calix transformatus in Sanguinem," etc. In some instances the prayer for the descent of the Holy Ghost is changed into a prayer for the descent of Christ; as, for example, in the first (=second) Sunday after Easter: "Christe . . . his sacrificiis propitius illabere, bisque benedicturus descende." The corruption sometimes takes a curious turn: thus on July 25 the Post-Pridie prays that by the intercession of St. Christopher the offerers may be filled with the Holy Ghost. We may gather on the whole that Ximenes, who (like Bona) must have considered the prayer for any change after the words of institution a detestable error, softened the expression in many cases, and omitted it in many others; though enough is still left to show us what the original design of the prayer was. SEE LITURGY. (J.H.W.)