Following up my post on "begging the question", here are some more common logical fallacies that often pop up when discussing the faith with others:
Straw man – When someone sets up a “straw man” argument, he takes the opponents weakest argument (or creates it), and attacks it as though the entire foundation rests on that argument. An example of this would be if someone makes a case against confession to a priest by arguing that, if God knows everything and, therefore, knows my sins, it makes no sense to have to articulate them in confession. The reasons Catholics confess to a priest are much more substantial than (and have nothing to do with) informing God of our sins. This is a false, weak argument refuted to discredit a much more complex idea by ignoring the greater points.
Shotgun approach – In a shotgun approach, one throws as many arguments at his opponent as possible, knowing that it will be difficult, if not impossible for his opponent to answer them all (especially if there is a time restraint), implying that any unanswered challenges prove a weakness in the other’s position. For instance, upon discovering that you are Catholic, an ambitious anti-Catholic may launch into a tirade like this: "If you think the Catholic Church is in accordance with Scripture, where does the Bible tell about Mary being sinless, Mary not having other children, praying to saints, Purgatory, mortal sins, calling priests father, indulgences …" Each of the topics listed requires a serious and in depth study of Scripture. The challenge is designed to exhaust and overwhelm the opponent. Over a year ago, I was in an e-mail conversation with a preacher about infallibility. His protests were falling flat, and it was obvious that the Catholic truth was prevailing, so in a move of desperation, he sent an eight-page list of "proofs" against infallibility that he had pulled off various anti-Catholic sites, convinced this would overwhelm my attempts to respond. My first step (as should be yours in such a case), was to call his foul and inform him that, if his argument has merit, he shouldn't have to resort to tricks to make his point. Then, I shocked him by sending an eleven-page response, addressing each and every one of his points. In retrospect, I probably shouldn't have given his e-mail that dignity (it was a very weak piece of work) because it could have invited further shotgun attacks. In this case, however, he wrote back and said he needed more time for study on the subject and that he would get back with me. This was the last I heard of him.
False dichotomy – In a false dichotomy, one gives only two possibilities, and neither is usually very appealing, in order to force agreement with the more desirable. This approach, ignores, however, other legitimate possibilities: “You are either in support of this tax issue or you are against improving our highways.” The question precludes the possibility that their might be a means of improving the highways without a tax increase. In matters of faith, this fallacy often looks something like this: "Look, it comes down a simple question of whether you want to go by the Bible or to follow the traditions of men." There is another option, of course, which is to follow the Traditions of Christ that have been delivered once-for-all through Scripture and Tradition and have been preserved through 2,000 years by the Catholic Church, through the guidance of the Holy Spirit.