Charles Halton taught me something about making a good argument, and it has stuck with me. I took a couple of his M.Div. classes, and I would frequently observe this exchange (I might have been the student once or twice):
Student: "But isn't it possible that …"
Charles: "Yes, anything is possible."
No matter the question, if it was prefaced with "isn't it possible," this was his response. After a moment of awkward silence, he would (usually) smile and go on to explain the moral of the story: the best explanation is not the one merely possible, but the one that is most probable. "Isn't it possible" is often irrelevant. Of course people will disagree about what makes an argument "probable," but this is where the conversation should take place.
It took a while for this important point to sink in; it might have sunk in a little more quickly if he would have said it like this: