I was wrong when I stated that it was the Holy Spirit that effected the change of the bread and wine into the body and blood of Jesus as you are in error with your statement from above.
According to the Summa from St. Thomas Aquinas who wrote: "
On the contrary, Ambrose says (De Sacram. iv): "The
consecration is accomplished by the words and expressions of the
Lord Jesus. Because, by all the other words spoken, praise is rendered to
God,
prayer is put up for the people, for kings, and others; but when the time comes for perfecting the
sacrament, the
priest uses no longer his own words, but the words of
Christ.
Therefore, it is Christ's words that perfect this sacrament."
So we see that it is Christs own words that cause this to happen.
The Holy Spirit however is indeed involved as I suspected. The Second Vatican Council rightly proclaimed that: . "For the most holy Eucharist contains the Church's entire spiritual wealth: Christ himself, our passover and living bread. Through his own flesh, now made living and life-giving by the Holy Spirit, he offers life to men .2 Consequently the gaze of the Church is constantly turned to her Lord, present in the Sacrament of the Altar, in which she discovers the full manifestation of his boundless love as a matter of course".