Finally, and especially, a good commentator on the Scriptures will come to his task "well acquainted with the whole circle of Theology and deeply read in the commentaries of the Holy Fathers and the Doctors, and other interpreters of mark." (Encyclical of Pope Leo XIII, Providentissimus Deus). This is an essential qualification in an exegete; it is not merely an advantage, it is absolutely indispensable, a sine qua non. This by reason of the very nature of the Scriptures. They are not ordinary books; they are the inspired Word of God; they have a dual authorship,—divine and human. Their purpose is to teach us divine truth, and, to quote again from the same source, "the language of the Bible is employed to express, under the inspiration of the Holy Ghost, many things which are beyond the power and scope of the nature and reason of man—that is to say divine mysteries and all that is related to them." The Pope quotes at length to the same effect from the writings of the Fathers of the Church, especially from St. Irenaus,* St. Jerome, St. Augustine*. Then, he goes on to say: "Wherefore the first, the dearest object of the Catholic commentator should be to interpret those passages which have received an authentic interpretation either from the sacred writers themselves, under the inspiration of the Holy Ghost (as in many places of the New Testament), or from the Church, under the assistance of the same Holy Spirit, whether by her solemn judgment or her ordinary and universal magisterium (Council of the Vatican. Session 3, Chapter 3)—to interpret these passages in that identical sense, and to prove by all the resources of science, that sound hermeneutical laws admit of no other interpretation. In other passages the analogy of faith should be followed, and Catholic doctrine, as authoritatively proposed by the Church, should be held as the supreme law; for, seeing that the same God is author both of the Sacred Books and of the divine command to the Church, it is clearly impossible that any teaching can by legitimate means be extracted from the former, which shall in any respect be at variance with the latter." These words put the Catholic position clearly. * St. Irenaus, Bishop of Lyons, lived in the second century. *St. Augustine-354-430