Faith and reason are in harmony when God is understood as truth, beauty, goodness and universal reason, which are there for all human beings to grasp. Reason and Original Sin (the knowledge of the difference between good and evil) are both blessings and curses created by God and bestowed upon man. Both were given for a purpose. To fail acknowledge and exercise both is a rejection of God.
In an interview that was published in 1997, Joseph Cardinal Ratzinger (now Pope Benedict XVI) stated: Part of faith is also the patience of time. The theme you have just mentioned - Darwin, creation, the theory of evolution - is the subject of a dialog that is not yet finished and, within our present means, is probably also impossible to settle at the moment. Not that the problem of the six days is a particularly urgent issue between faith and modern scientific research into the origin of the world. For it is obvious even in the Bible that this is a theological framework and is not intended simply to recount the history of creation. In the Old Testament itself there are other accounts of creation. In the Book of Job and in the Wisdom literature we have creation narratives that make it clear that even then believers themselves did not think that the creation account was, so to speak, a photographic depiction of the process of creation. It only seeks to convey a glimpse of the essential truth, namely, that the world comes from the power of God and is his creation. How the process actually occurred is a wholly different question, which even the Bible itself leaves wide open. Conversely, I think that in great measure the theory of evolution has not gotten beyond hypotheses and is often mixed with almost mythical philosophies that have yet to be critically discussed.
How does that solve your problem of using logical fallacy as argument in favor of evolution?
Are you not allowed to admit that logical fallacy is the basis for evolution if the Pope doesn't?