Cum jam nonnullas meas lucubrationes cum epigraphe. De sacris Aedificiis a Constantino Magno constructis, typis commisissem, ejusque occasione toto terrarum orbe celeberrimam Vaticanam basilicam descripsissem, illud inter plura notandum venit quod prisci fideles flexis genibus venerabundi per gradus ad eamdem ascendere consueverunt. Qua de re cum R. P. Josepho Maria Thomasio presbytero congregationis clericorum regularium communi amico, veterumque sacrorum rituum nostri aevi eximio perscrutatore, cum forte collocutionem haberem, dixit mihi, se in sermone 7 sancti Leonis Magni de Nativitate Domini vocem ARAE animadvertisse, quam per errorem ibi positam esse autumabat. Quamobrem meae curae, meaeque indagationi illius dubii solutionem relinquebat. Libentissime amici instantiis obsequi proposui ; propterea primo in loco ad impressos perquirendos codices me converti. Hos si tibi omnes recitavero, gravem me futurum minime puto, cum tu litteras ames. Antiquissima igitur sermonum sancti Leonis impressio est illa Coloniae facta anno 1551; in-folio, quae in eadem civitate et forma anno 1569 prodiit ; deinde ejusdem sancti Leonis sermones in lucem fuerunt emissi Venetiis anno 1553, qui in eadem forma, in eadem civitate, anno 1573 iterum prodiere. Deinde anno 1566 Lovanii iidem sermones editi fuerunt in quarto ; et postea Antuerpiae anno 1583 recusi similiter in quarto. Anno vero 1633 omnia sancti Leonis Opera ex Lugdunensibus typis in lucem emissa, quae una cum sancto Maximo ac quinque aliis Patribus anno 1652 ibidem fuerunt pariter recusa. Demum Parisiis anno 1675 ab eruditissimo viro Paschasio Quesnel presbytero congregationis Oratorii, appendicibus, dissertationibus, observationibusque illustrata, e prelo exierunt. Omnes has editiones, quae ad meas pervenere manus, accurata legi attentione, omnesque in se vocem ARAE continere comperi. Quare ad indagandos manuscriptos codices statim animum addixi; propterea Vaticanam adivi bibliothecam, in qua cum manuscriptis abundet codicibus, tum maxime propter necessitudinem, quae tunc temporis cum bon. mem. Emanuele a Schelstrat primo ejusdem bibliothecae intercedebat custode, utque sperabam aliquid in eadem me esse reperturum; at spes me fefellit ; quoniam nihil adinveni. Ex hoc non perterritus animo, immo audacior factus, ad alias, tam in Urbe, quam extra eam invisendas, ac ope amicorum revolvendas bibliothecas, me converti. Inclytas Barberinam, et Otthobonam, necnon Angelicam adivi bibliothecas, et licet in eis manuscriptos codices, in quibus sancti Leonis erant sermones, invenissem, nihilominus ob illorum antiquitatem venerandi minime erant, in eisque nihil, nisi ARAE vocem, observavi. Postea Mediolanum reverendiss. P. Eustachio a Sancto Ubaldo ordinis sancti Augustini discalceatorum, ac sanctissimae Inquisitionis in illis partibus consultori, deque republica litteraria optime merito litteras dedi, ut in Ambrosiana indagaret bibliotheca, an aliquis adesset manuscriptus codex, qui S. Leonis sermones contineret, et praefatam ARAE vocem in eis animadverteret. Respondit amicus se diligenter perquisivisse codices, atque in eis ARAE vocem legisse. Mox tibi etiam dedi litteras, ac responsum accepi, te in codice signato numero 126 praefatum reperiisse sermonem, ac in eo vocem ARCAE expressam esse ; quare amanuensis errorem putabas, qui loco AREAE ARCAE scripsisset, commutando litteram E in C ; codicemque illum unum supra nonaginta sancti Leonis continere sermones cujus codicis initium est : Incipiunt sermones sancti Leonis papae. In primis de jejunio mensis decimi. Si fideliter, dilectissimi atque sapienter creationis nostrae intelligimus exordium
When I had already committed to the press some lucubrations of mine under the title On the sacred Buildings constructed by Constantine the Great, and on that occasion had described the Vatican basilica, most celebrated throughout the whole world, this among many things came up as worthy of note, that the faithful of old were accustomed to go up to it by the steps reverently on bended knees. And when I happened to be conversing on this matter with the Reverend Father Giuseppe Maria Tommasi, priest of the congregation of clerks regular, our common friend and in our age an outstanding investigator of the ancient sacred rites, he told me that in sermon 7 of St Leo the Great on the Nativity of the Lord he had noticed the word ARAE, which he held to have been put there by mistake. Wherefore he left the solution of that doubt to my care and my investigation. I resolved most willingly to comply with my friend's urgings; accordingly in the first place I turned to searching through the printed books. If I recite all these to you, I do not think I shall be at all burdensome, since you love letters. The most ancient printing of the sermons of St Leo, then, is that made at Cologne in the year 1551, in folio, which came out in the same city and format in the year 1569; next the sermons of the same St Leo were published at Venice in the year 1553, which appeared again in the same format, in the same city, in the year 1573. Then in the year 1566 the same sermons were published at Louvain in quarto; and afterwards reprinted at Antwerp in the year 1583, likewise in quarto. But in the year 1633 all the Works of St Leo were published from the presses of Lyons, which, together with St Maximus and five other Fathers, were likewise reprinted in the same place in the year 1652. Lastly at Paris in the year 1675 they issued from the press, illustrated with appendices, dissertations and observations by the most learned man Pasquier Quesnel, priest of the congregation of the Oratory. All these editions, which have come into my hands, I read with careful attention, and I found that all contain the word ARAE. Wherefore I at once set my mind to searching out the manuscript codices; accordingly I went to the Vatican library, both because it abounds in manuscript codices and above all on account of the friendship which at that time existed between me and Emmanuel Schelstrate of good memory, first keeper of the same library, and as I was hoping that I should find something in it; but hope deceived me, since I found nothing. Not dismayed in mind by this, nay made bolder, I turned to visiting other libraries, both in the City and outside it, and to having them searched through with the help of friends. I went to the illustrious Barberini and Ottoboni libraries, and also the Angelica, and although I had found in them manuscript codices in which were the sermons of St Leo, nevertheless they were by no means venerable for their antiquity, and in them I observed nothing but the word ARAE. Afterwards I sent a letter to Milan, to the most reverend Father Eustachio a Sancto Ubaldo, of the order of the discalced of St Augustine and consultor of the most holy Inquisition in those parts, a man who has deserved excellently of the republic of letters, that he might inquire in the Ambrosian library whether there was any manuscript codex which contained the sermons of St Leo, and might take note of the aforesaid word ARAE in them. My friend replied that he had diligently searched the codices and had read in them the word ARAE. Presently I sent a letter to you also, and received the answer that in the codex marked with the number 126 you had found the aforesaid sermon, and that in it the word ARCAE was written out; wherefore you thought it the error of a copyist, who had written ARCAE in place of AREAE, changing the letter E into C; and that that codex contains ninety-one sermons of St Leo, of which codex the beginning is: Here begin the sermons of St Leo the pope. First, on the fast of the tenth month. If faithfully, dearly beloved, and wisely we understand the beginning of our creation