TO READ Genesis at all, you need at least to know the difference between the literal statement of historical fact, the metaphorical statement of historical fact, and pure allegory. There is a world of difference between the Book of Genesis and "Pilgrim's Progress," but there is also a world of difference between the Book of Genesis and a modern history textbook. If I say of a soldier who fought with great bravery in Libya that he fought with great bravery in Libya: that is a literal statement of historical fact. If I say of him, "He was a lion in Libya," it is presumably a metaphorical statement of the same historical fact. If, on the other hand, I make up an entirely fictitious story of a soldier who never existed and who fought like a lion in a battle which never took place, I am using language allegorically to express some truth which as likely as not has nothing to do with firearms. When we are told in the Book of Genesis that God brought all the animals before Adam that He might name them, it is possible to interpret the incident in any of these three ways: the Catholic would not take it in the third way; but no one would take it, unless he was very silly, in the first way. No one in his senses would suppose that God (in corporeal shape perhaps, and with corporeal noises?) assembled the patient beasts in an endless orderly queue and then left the unfortunate Adam to rack his brains for names for them. But the fact that it is not a literal presentation of history does not mean that it is not a presentation of history at all. God gave him "dominion over the beasts of the field and the fowls of the air"; that is the historical meaning; and it is a historical fact that we need to know if we are to understand our present plight. 

All that is not to say that it is always easy to decide what in Genesis is metaphor and what is literal statement; far from it; but at least it becomes clear that you can read Genesis as a historical document in a real and profound sense without getting embroiled in an irreconcilable conflict with a science with which the book has no concern. 

Conflict there may well be in individual or at given moments of history, yes; but not ultimate and irreconcilable conflict. The mind and tradition of Catholicism are plain here: you have to choose between a prudence which often looks like over-caution in acknowledging the progress of science and an eagerness for the advance of knowledge which may, in fact, be imprudent. Prudence, because what is at stake above all is the faith and the happiness of the "little ones." If you are cautious and slow, you may be tardy in incorporating new knowledge in the total of truth; but if you are hasty, you may find that the new knowledge, ill-digested and unwisely popularized, is leading the unlearned not so much to the new (and secondary) truth as away from the indispensable substance of the old. And that this last shall not happen is the first duty of the teaching Church. It is exciting and sometime profitable to gamble on a hypothesis; but not when eternity is at stake. Cajetan, the fifteenth-century scholar and follower of St. Thomas, states the traditional principle of Catholic Biblical study in this connection when he says that we should take the text as literal statement of fact unless it is clear from text or context that this is not the case; and we must include among the evidence from the text itself, if we are to be faithful to the thought of Cajetan's master, the compelling force of .a certitude concerning the relevant facts drawn from sources other than the Bible, sources such as science. But it must be certitude. Given the certitude that the world was not made in six days but in millions of years, it at once becomes clear from the text that the author in describing the creation is using the language of metaphor to describe historical events. Not to accept the scientific certitude here would be a treason to the truth; for truth is one. 

But certitude is one thing, and hypothesis, however attractive or probable, quite another. It is the mark of the laboratory mind to treat any fashionable hypothesis of the moment as though it were an unquestionable certitude. You may think that the Church, in its guardianship of the Bible, is simply fighting a rearguard action, gradually abandoning its former positions when science at last compels it to do so, but always reluctantly, always with a bad grace. But this is, at best, a one-sided view of the situation. To insist upon waiting until scientific hypotheses are really proven is not a treason but a service to the truth; there is such a thing as over-caution, yes; but behind the facts of history as anthropology sees them, there are other questions of greater importance, and there are the millions of "little ones" in the world to whom anthropology means little but these other questions everything; they must be guarded; if you begin too hurriedly to say that this and that is "only a metaphor," they may be led to suppose (quite erroneously but disastrously) that in some way the deepest truths which lie beneath the metaphor are themselves only a fairy story. The slowness of the grinding of the mills of God can be exasperating; but our Lord had harsh things to say to those who are a stumbling-block to the little ones; sometimes we tend to forget all about the little ones. 

Still, you may think that the Church is over-cautious; but, at least, do not think that when it does incorporate the findings of science and use them to interpret the Biblical text, you are witnessing a triumph of science over dogma. Nothing could be further from the truth. There is a world of difference between accepting new light on the manner in which eternal and therefore unchanging truth is presented to the mind of man and hushing up or even rejecting a part of that eternal truth because it does not seem palatable to a transitory mood. The former the Church must always do, because the Church believes in truth.‚—Gerald Vann.