text: Well, as I said, it's a matter of which you believe.  As you know, the Church teaches Jesus did intend to instruct the Apostles via the Words of Institution.  In fact, theologians thought so even before Aquinas, and there is evidence that the Apostles themselves believed in transubstantiation, without knowing the metaphysics of it.  Remember the reaction of Jesus' disciples when they first heard him talk about eating his body.  They accused him of advocating cannibalism.  When he persisted, some walked away.  Belief in transubstantiation is a central tenet of Catholicism.  That being the case, you not only left the priesthood, but by rejecting transubstantiation, left Catholicism as well.