I hesitated in posting this, because the discussion is not really even; for 'The Professor' it is a personal point, defending reasoning actually made. For me it is not; it's rather more abstract, an interesting case, 'in the wild', of an interesting form of fallacious reasoning, namely, the inference from a claim of inverse ratio ("The more x, the less y, and vice versa") to a claim of exclusion or categorical distinction ("x and y are distinct categories of things, where x is the category of things that have a given property, and y is the category of things that don't have it"). I considered simply leaving the Evangelical Realist's post alone, conceding the discussion but not the point; my point stands on its own, and the responding post simply reiterates the mistake in an even more obvious form. In the end I decided to post it for three reasons: because I think it needs to be made very clear that this is indeed a fallacy, and apparently I did not make it clear enough before; because I've begun to wonder whether the fallacy might be more common than I had originally thought, in which case attention needs to be drawn to it so that it will stop masquerading as good reasoning, wherever it is found; and because 'The Professor' is clearly not stupid, so I should do him or her the courtesy of pointing out a flaw that, if uncorrected, might reflect badly on all the reasoning that goes on at the Evangelical Realism blog. Feel free to let me know if you think this was a mistake on my part, since occasions like this are likely to arise in the future. (I should also say that, unlike The Professor, I don't think the inverse ratio claim is intended by G & T to be anything more than a rhetorical device, one elaborating the deliberately ironic title of the book. If that's so, it is not a rigorous account of faith as G & T see it, and particularly as Geisler sees it, but merely something to give the 'gist' or general idea. But I fully understand that views may differ on this, and in what follows I simply assume that the inverse ratio claim is a strict and precise account of faith for G & T.)
The whole first part of the post is not relevant to my point; the complaint is that one might think from what I said that the author was arguing "against the idea that faith and evidence can co-exist." But, after talking about the way his or her position allows for a form of faith compatible with evidence, the author goes on to say, "However, that’s what I say, not what Geisler and Turek are saying," and then to distinguish entirely the notion of faith G&T use from the one the author uses. Exactly. My post was on the curious tendency to attribute to certain religious believers a view of faith in spite of the actual evidence about what they believe; this was done with Macht and it was done again with Geisler. The post I was responding to explicitly attributes the 'faith is belief without evidence' to Geisler, despite the fact that Geisler is clear, on many occasions, that his view is that (1) faith is compatible with evidence, and in fact requires it; (2) that it is a form of belief that occurs where the evidence is incomplete; and (3) the quality of faith increases with an increase in the evidence. It is this, in fact, that is the whole argument of the book the post mentions, I Don't Have Enough Faith to Be an Atheist, namely, that Christianity is a higher quality and more rational form of faith than atheism is because it is a form of faith that has more evidential support.
The point about the analogy is also not particularly relevant to the basic point of my argument, since the analogy was just as a clarificatory example for the logical point about how claims of inverse ratio often do not allow us to conclude with claims of exclusion (e.g., that faith is belief without evidence); Geisler makes an explicit claim of inverse ratio, and this is evidence that he would reject the claim of exclusion. The analogy I gave is sufficient to illustrate the point. But it is an interesting question what However, the alternative analogy proposed is certainly not a better analogy:
Debt corresponds to the gap between the bills you owe and the bills you’ve paid. As the percentages of paid bills goes up, the percentage of unpaid bills goes down, and vice versa.
So the idea is that unpaid bills are to faith as paid bills are to evidence. This is indeed a claim of inverse ratio; it's a necessary one, in fact. But then the Evangelical Realist ruins it by saying, yet again, that this claim of inverse ratio is a claim of exclusion. Yet again we find the elementary mistake of treating a claim of inverse ratio as a claim of exclusion.
We can see this point by clarifying the analogy somewhat. An unpaid bill is a debt; that is one way in which we use the term 'debt'. But the sort of debt the author has in mind appears to be 'debt' in the sense of your financial state. Consider: while it is true that as your bills are paid your debts (in the first sense) decrease, this is simply a trivial truth, that paid bills are no longer unpaid. But this also has no connection to "the gap between the bills you owe and the bills you've paid"; your debts in this sense are simply the bills you owe, nothing else, and to determine your debts in this sense you don't look at bills you've paid at all. The bills you've paid are irrelevant to the question of how many bills you still owe. Thus, although paid bills and unpaid bills are in inverse ratio, they are independent. The reason for this is that they have different causes: bills are paid because you pay them, but bills are unpaid simply because creditors require them and they aren't paid. This is clearly not analogous to Geisler's claims about faith, in which faith is not the difference between what your evidence supports and what you believe, i.e., an epistemic debt, but instead the difference between the degree to which your evidence supports the conclusion and that degree of evidential support which undergirds any sort of conclusion with certainty. This allows Geisler and Turek to say that the less evidence you have (i.e., the less evidential support you have), the more faith you have (i.e., the less closely your belief approximates knowledge), and vice versa.
Now it does not follow from this that faith is belief without evidence, and clearly so. To determine on this formula how much faith someone has, we look to see both how much evidential support and how this compares to a case of knowledge. So suppose that someone believes some belief B (it doesn't matter much what it is), and the available evidence supports that with 95% certainty. The quantity of faith is determined by taking this degree of evidential support and comparing it with the 100% case; and we find that they are not all that different. It doesn't need much faith, and it's almost knowledge; but we do believe it with a bit of faith. Now it is clear when we do something like this that faith, understood in this way, is not belief minus the evidence; it's the belief we have on our evidence, given that our evidence does not give us 100% certainty. You cannot even determine how much faith a person has until you've determined how much evidence they have. That is what the inverse ratio claim requires; and because of it we cannot say that faith is belief without evidence.
Now, there are certainly problems with this view of the matter; I would argue, for instance, that it is based on a false (albeit common) view of evidence, and an equally false (but even more common) view of belief. But it is absurd to insist on reading Geisler as saying that faith is belief with evidence, when Geisler's obvious view is that faith is belief with evidence that does not yield certainty, to the extent it does not yield certainty. The Evangelical Realist tries to wriggle out of this by saying:
Knowledge and faith can exist side-by-side, but even when you have both of those categories existing side-by-side, the knowledge category contains the things supported by verifiable evidence, and the faith category contains the other stuff.
But (1) this is manifestly not what Geisler and Turek are saying, and it highlights even more clearly the elementary mistake being made. (1) They do not ever equate faith with absence of evidence, so that faith is the category of things not supported by evidence, but with the difference between the degree of evidential support for your position and the degree involved in cases of knowledge. This is entirely different. For Geisler and Turek, faith is not 'the other stuff', the things not supported by verifiable evidence; faith is a fact about the things supported by verifiable evidence, namely, the difference between the support they have and the support a case of knowledge has. (2) One might as well say that cold and hot, because they are in inverse ratio, are two categories of temperature existing side by side, a hot category where there's mean molecular motion and a cold category where there's none. That's clearly a confused account of the inverse ratio involved. What puts hot temperatures and cold temperatures in inverse ratio (so that the hotter it gets, the less cold it gets, and vice versa) is not that they are two categories of things, but that they are a single scale looked at from two directions. So it is with this. There is a reference point: evidential support at 100%. For anything less than that we can characterize our state in two different ways: we can say how much the evidence goes beyond complete lack of evidence; and we can say how much the evidential support for our belief falls short of certainty, i.e., fullest evidence. In other words, we can regard the degree of evidence itself or the degree of faith. The two vary inversely, but they are not different categories of things, but different descriptions of the same thing: one by how much it exceeds zero evidence and the other by how much it falls short of 100% evidence. Faith on this view is not the beliefs that don't fall into the category of "supported by verifiable evidence".
As I said, I think this is not the right sort of account of evidence and faith. But it is very important to be clear that the move that the Evangelical Realist makes is a clear and definite error of reasoning, one in which claims that X and Y are in inverse ratio are taken as necessarily saying that X and Y are two categories, each including only things that lack the other. What is more, it is an elementary mistake. Taking it seriously would lead to utterly absurd results all across the board.