This is the 10th century Pontifical of Poitiers. In the
section for Making of a Catechumen, at the giving of the Creed, we
have the Creed written in Greek in Latin letters, and then, an
interlinear Latin translation.
In the transliterated Greek it just
reads (on fol. 55v) as:
“Ke is to Penuma
to Agion to Kyrrion ke Zoopion to ek tu Patros ek Porreugomenon.”
[“And in the Holy
Ghost, the Lord and Life-Giver, from the Father Proceeding.”]
In the Latin
interlinear text, however, we notice something curious. In the
original Latin text it just reads as:
“Et in Spiritum
Sanctum, Dominum et Vivificantem, ex Patre Procedens.”
[“And in the Holy
Ghost, the Lord and Life-Giver, from the Father Proceeding.”]
However, you notice
that a later hand, with darker ink, has tampered with the text, so
that we have the following emendation:
“Qui” added to
before “ex” and “Filioque” added immediate after “Patre”
and the original “procedens” has been erased, and the form
“procedit” put in its place.
The Gelasian form of
the Latin Symbol generally read simply as “ex Patre Procedens” or sometimes "Procedentem".
Nevertheless, the
Pontifical was made in the 10th Century in Poitiers, for
the Bishop of that City, and the original 10th Century
text simply had the Credo in Greek (with the interlinear gloss having
a faithful translation, absent a much later interpolation).
HOWEVER, if we go
only to the page after the Greek Credo is completed (56v), things get even better.
There, the Credo is to be recited formally in Latin (while the
interlinear text in Latin was not a formal recitation), with the
formal Latin Symbol / Credo in the relevant section saying:
“Et in Spiritum
Sanctum, Dominum et Vivifcatorem, ex Patre Procedentem.”
“And in the Holy
Ghost, the Lord and Giver of Life, from the Father Proceeding.”]
No interpolation was
attempted. So, what happened? Well, whoever took the book, and much
later interpolated the interlinear Latin, apparently didn’t do a
very thorough job; he simply added the forbidden “Filioque” only
to the interlinear, and left the formal Latin a page later
uncorrupted!
When was the
interlinear text corrupted? My guess is in the 11th
Century when other cataclysmic changes happened.