Oration of Gregorio de Valencia,

Truly, although it is difficult, as we have said, to distinguish true teachers from false ones, the fact that we are not commanded in vain by God to exercise a choice of such teachers, and above all to be on our guard so as not to be deceived by the false ones, ought to be sufficient argument that a suitable method for this task is available to us. And to say nothing now of other signs which have been divinely indicated to us for such judgment, that sign seems to me sufficiently illustrious (if its entire power is deeply explained) which Irenaeus shows us from the Apostle Paul in those words which I recited at the beginning. "The Apostle," he says, "teaching, says, 'God has set teachers in the Church.'" 1 Corinthians 12. Surely those are to be considered legitimate teachers (says Irenaeus) who have been placed in the Church by God to teach; those are false to whom that office has not been imposed by God. How great a power this mark has, we must briefly