Three philosophers—Bob, Sue and Jim—are sitting around discussing whether or not they think they there is life on other planets. Before the argument begins and before each of them starts putting forward their views, they lay their cards on the table. Bob says that he is neutral on the question; he doesn’t know whether or not there is life on other planets—but that he is open minded and willing to be convinced. Sue starts by saying that there must be life on other planets while Jim says he doesn’t think that there could be life on other planets at all. So the argument gets underway, and the three of them hammer it out for an hour or so: Sue and Jim give arguments for and against while Bob asks clarifying questions waiting to be swayed one way or another.
But how neutral is Bob really? He says that he hasn’t made his mind up yet and that he’s waiting to be convinced one way or another, by whichever argument is most compelling. But what will actually convince him? What are his criteria for “convincing arguments”? What will count as being the clincher in a debate? Perhaps Bob is thinking: “I’m open-minded until I actually see an alien for myself”; or maybe he’s thinking, “I like Sue’s argument more: she’s much more passionate about the topic.” Bob’s neutrality has a limit and a context: he is neutral but only until his own predispositions to the question are fulfilled. He is neutral according to his own criteria.
The same in fact goes for Sue and Jim too. Either they’ll be so stubborn that they’ll both seek to find flaws in each other’s arguments no matter what. Even if Jim were to produce an alien autopsy report, Sue could still question the validity of the autopsy: coroners after all are not infallible. Both Sue and Jim will bring to the argument an attitude towards the question and will try to find arguments to support that predisposition.
But let’s imagine for a moment that Jim in fact is also open-minded enough to be swayed by the debate and concedes that Sue has raised some compelling mathematical calculations that makes him reconsider his position. But in this case, Jim has his own set of criteria that serve as a reason for him to reconsider his position. Jim is swayed by a mathematical probability argument: “Out of the billions of galaxies out there, chances are that some of them have life on them just like earth.” Jim is swayed by the probability argument—but at the same time, Bob is not. In order to accept the probability argument, you have to accept that life is just a random occurrence he reasons. Since he does not believe life on earth is random, then a probability argument does not sway him at all.
Everyone approaches an argument—even if they claim to be neutral and open-minded—with a predisposition to those arguments. Either our minds are already made up or we have a set of criteria by which we will allow our minds to be made up.
All arguments for the existence of God—including the cosmological, design and ontological arguments—are, at their root, arguments which rely on a theory of knowledge. Whether you are for or against God’s existence, or for or against the cosmological argument, your reasons for accepting or rejecting such arguments will be drawn from ideas about how you can go about knowing something.