In my first commentary on the Dennett/D'Souza debate I pointed out that there were two different kinds of rhetoric being employed, by Dennett and D'Souza, and on the broader, cultural level.
I called these "scientific rhetoric" and "political rhetoric".
Scientific rhetoric aims to improve our understanding of the question at hand, whether or not it motivates us to do anything. Political rhetoric aims to move us to action, whether or not it deepens our understanding.
This is important, in the current debate, partly because it isn't completely clear which kind of rhetoric actually applies. The official question—Is God a Human Invention?—is phrased as a topic for scientific argument. It sounds like a question of understanding.
But the real question—the one that surfaces rather soon, and the one that actually gets debated—is "Should We Believe in God?".
That question is centered on "belief", and it isn't at all clear whether belief, in this context, is a matter of understanding or a matter of action.
If I say to you, "I don't believe I have a wrench that size," or if a scientist says, "I believe that string theory is going to be constructive," the word is being used in a scientific sense. It is being used to indicate a current guess that is, nevertheless, rooted in understanding, and open to understanding-based argument.
If you respond by saying, "That's the size of the bolt on the lawnmower you repaired last Friday," or "Have you seen the recent experimental evidence?", you are addressing the question scientifically, in the way it is framed.
If you respond, on the other hand, by saying "Do you want the neighbors to think you have an inadequate workshop," or "If you continue to believe that you're going to lose a lot of research money," you are missing the point of the word "belief" in those contexts.
I simply can't change my actual belief about what wrenches I own because I want the neighbors to think well of me, and a scientist can't change his or her belief about string theory because of research money. (Both I, and the scientist, could decide to lie about our real belief for these reasons, but that is a separate issue.)
So, in contexts which range from the mundane and everyday (my wrench) to the sublime and highly technical (string theory), the use of the word "belief" falls, quite naturally, into the realm of scientific rhetoric.
But it isn't so clear where it falls when it involves belief in God.
On one hand, people talk about belief in God as though it were normal belief. They give reasons for and against it, offer evidence pro and con. They have debates about it with non-believers, and center them around propositions like "God is a Human Invention," which seem to be about a normal, run-of-the-mill kind of belief.
On the other hand, it often seems like believing in God is an act of some kind, rather than a state you find yourself in.
Often people are called upon to make a decision to believe in God, as though belief were an act, something they could change at will. Depending on the denomination, people can be blamed, or even punished, for believing wrong.
This is a significantly different use of the word "belief", and it has definite implications for the kind of rhetoric that is applicable, as well as the kind of conclusion one can expect to draw, from the debate.
If, for example, we are talking of the kind of belief that I have about my wrench, then scientific rhetoric is the most appropriate to the subject.
This normal type of belief, about a fact, can only be changed through deeper understanding; it is not something I can be motivated to do, one way or the other (though unconscious motivations may warp my judgement, if they are based on false information).
If, however, we are talking about another use of the word belief, which is not a belief about a fact, but an act like joining a club, or choosing which team you're pulling for, then the appropriate rhetoric is political, and it should be focused on our motives, rather on the evidence or understanding.
This doesn't mean that either party is going to use only one or the other approach.
I've already pointed out that Dennett began the debate by quite appropriately using political rhetoric to correct an irrational subconscious prejudice against his side of the debate, even though I am pretty certain that he believes the debate to be about a question of fact.
But the interplay of the two different rhetorics—how they are used, and when, and for what purpose—can tell us a good amount about the subtext of not only this debate, but the larger issue itself.