Some time ago, I was talking with a friend, and he brought up how a mutual friend of ours had suggested that it is possible that Moses, the Biblical character from the Old Testament, did not historically exist. Rather, that he is simply a literary character used to explain Israel's liberation from Egypt and settlement in the Holy Land. My friend asked me this to get my opinion on whether or not this is doctrinally acceptable. My answer, however, is not as simple as a "yes" or "no". Perhaps it is not, I have not investigated to see if the Church has any magisterial teaching on this matter, but I would like to take this opportunity to comment on interpreting Scripture in general as a historical text.
To begin, I'd like to say that I greatly respect this mutual friend of ours, and I know that either he was joking when he said it, or he has good reason to believe it's a possibility. This mutual friend was a seminarian, and has studied a Master's degree in history. He is also a person I know to uphold doctrinal orthodoxy, even if it is unpopular. So whether or not I agree with his opinion, I believe it is respectable simply from his credentials and merits. However, since I do not have much knowledge regarding this topic, I will instead focus on another topic where I am knowledgeable of the magisterial teaching and current scientific theories regarding the matter: Creationism versus Evolution.
Whenever we bring up a question regarding Faith or Morals, our first step must always be to pick up a Catechism, or in general see what the Magisterium of the Catholic Church has to say on the matter. Not just to find a definitive statement, but especially to find the reasoning. If the Church has an official teaching on such a matter of Faith or Morals, we must either subject our opinions to that teaching, or reject the teaching and Christ's Church (i.e. reject Catholicism). It's not necessary to know why things are the way they are, only God knows that for sure. But we must be humble like children before the infinite wisdom and knowledge of God. If, on the other hand, the Church does not have any definitive teaching on the topic, then we are free to take a variety of opinions so long as they are compatible with the rest of Catholic Doctrine.
To explain this with our example, the Church has no definitive teaching on the question of Creationism or Evolution; and in fact, She shall never have such a teaching, as this is a question of science and not Faith or Morals. As such it lies strictly outside the jurisdiction of the Church's teaching authority. You can easily discern this by contemplating whether believing in one or the other contradicts any doctrine for our salvation, which neither Evolution nor Creationism does.(1) As such, it is not problematic for a Christian to believe either of these theories. God will not judge either of these people based on their beliefs on how species came to be as they are.
So the question now stands, if the Church has no official teaching, and therefore which you choose to believe has no direct effect on your salvation, which should you believe? Should you believe the interpretation of Scripture that is more true to the literal meaning, or the interpretation that has been harmonized with modern scientific discoveries? My view on the matter may be controversial, but I believe you should believe whatever helps you to grow in faith and charity. If it helps your faith to believe in Theistic Evolution, then do so. If you find it difficult to harmonize Evolution with Biblical inerrancy then go ahead and believe in Creationism. But most importantly: be respectful of those who disagree with you, and recognize that this one belief of yours in personal. Do not convince others that this is the only thing that a good Christian can believe. And to carry my point home: don't use your personal belief as an excuse to hinder scientific discovery on the matter. If you are truly convinced of your opinion, let the truth find its way out, as it eventually will. But do not be afraid of scientific discovery, for truth cannot contradict Truth.
Finally, since I'm bound to get some commentary on the matter, I will publicly state that I accept Theistic Evolution. I think that this theory helps to explain certain accounts in Genesis, such as where Cain's wife comes from; but as a lay person, I don't wish to be so naïve as to proselytize others with my belief. Only God knows the ultimate truth behind these sorts of things, and on the final day when the truth is revealed to us, we should be humble in accepting whatever may be the case. So again, believe what you want, but accept that the Church has no official standing on these matters, that scientific theories are imperfect and subject to change, that you may be wrong, and above all that it's ultimately not that big of a deal.