McGrew's point was pretty obvious and seemingly good: faith is based on evidence, at times very good evidence. He cites a 99.93% success rate for parachuting, meaning that roughly seven out of ten thousand events are a failure. That's good evidence that someone going parachuting will survive the risk of his life, no doubt. The case McGrew makes is that closing that risk gap and believing one will land safely in a jump is faith--trust in the circumstances that is not reducible to hope.
Yesterday I said McGrew was just wrong about this. I think, frankly, that the mature view of the circumstance is that someone is jumping out of a plane knowing that there are problems seven out of ten thousand times and hoping that you're in the lucky majority. I simply don't think people actually have to close the risk gap in order to engage in risky behaviors. I also noted that most people are unlikely to possess the maturity to assess dangerous situations this way. (Note: I'm not entirely sure of this fact, not possessing relevant data, but I hope my intuition on the matter isn't too far astray and doubt it is given where I'm about to go with this.)
So this raises a good question: What allows people to take the plunge anyway? I think for the purposes of this discussion, which I expect McGrew and most Christians would agree are fair, we'll assume that the person is not simply ignorant of the risk, although that's likely true in many cases. McGrew says that what makes it possible is faith that isn't hope. If he's right, that's ugly for faith.
There is a well understood psychological phenomenon that explains how someone might decide to do something heedless to, though in full knowledge of, the risks involved. Colloquially, we hear it as, "It won't happen to me." Psychologists call it optimistic bias," a common cognitive bias that causes a person to believe that they are less at risk of experiencing a negative event compared to others," as Wikipedia puts it. In this case, optimistic bias would be (irrationally) concluding that one is among the 9,993 because the 7 failures are other people.
And I'm glad I turned to Wikipedia for a definition here (I helped conduct a research study in optimistic bias regarding smoking in pregnant women while an undergraduate, so I was already familiar with the concept). The Wiki is immediately poignant here, and so I'll quote the rest of the first paragraph, bold added for emphasis, citation notes left in place for reference.
There are four factors that cause a person to be optimistically biased: their desired end state, their cognitive mechanisms, the information they have about themselves versus others, and overall mood. The optimistic bias is seen in a number of situations. For example: people believing that they are less at risk of being a crime victim, smokers believing that they are less likely to contract lung cancer or disease than other smokers, first-time bungee jumpers believing that they are less at risk of an injury than other jumpers, or traders who think they are less exposed to losses in the markets.Here, then, we get some powerful reasons to believe that optimistic bias is likely to be in play regarding the feeling of trust that enables an inexperienced skydiver to jump from a plane. If that's what McGrew thinks makes a good example of faith that isn't hope, I'm glad to let him have it. As I've said before: faith is a cognitive bias, or at least it is intimately identifiable with them.
Of course, the analogy of the skydive is a pretty bad one to use regarding faith in God, but that hardly helps McGrew's notion of faith. First, we know--the same way that we know, and do not have faith in, the fact that chickens exist--that there are parachutes and that parachutes work when successfully deployed. We do not know God exists in this way, and even if we allowed space for the idea that God does exist, we don't know that God does anything. Second, optimistic bias probably only constitutes a modest, but significant, part of the Christian's faith, other biases being more prominent.*
It seems likely, though, that McGrew has unintentionally revealed that the way he conceives of faith is likely to be based in the consistent application of one or more cognitive biases. In the case of Christianity, not only does one have to close the gap from the justification of the evidence to the conviction of belief (largely, I would propose, by wishful thinking, a broader cognitive bias of which optimistic bias is an example), he also has to justify that the evidence supports Christianity at all, which is highly susceptible to confirmation bias. There may only be one cognitive bias at work in McGrew's conception of the faith of a skydiver, but there are several in operation in the faith of the Christian believer. By definition, cognitive biases irrationally close of the epistemic gap between the reality of the situation and one's beliefs about it.
Boghossian calls this "pretending to know something you don't," and we can discuss if that's an unfair characterization of it in light of the fact that the faith-filled epistemic gap is very likely to stuffed with the results of various cognitive biases. Pretending, generally, may not be the right word for this since our biases are not intentional. For this reason, it is a strong and accusatory word, and it's unsurprising that Christians recoil from it and take rather serious offense to it.
In my mind, though, there is a key difference between mere cognitive biases and the special one called faith, and it is assent. Typically, one does not actively assent to the results of one's biases. Instead we are blind to them and rationalize them somehow. Faith, though, by the Christian definition for it requires full assent, 100% agreement. Conviction by faith, then, is the rationalization for those biases, and it is one that according to Christian beliefs must be chosen intentionally. If faith isn't pretending to know something you don't know, then it is a label for the mechanism by which you act as if you know something you don't know, and those are near enough to the same thing to be getting on with. The only distinction is that articles held in faith are believed sincerely as a result of the faith itself.
Boghossian may be wise, then, to add a short addendum to his take on faith. Perhaps it's better to see faith as "pretending, in full sincerity, to know something that you don't."
*Optimistic bias in Christian beliefs being chiefly that, among those who still believe this kind of thing, they're more likely to go to Heaven (roughly 70% of Christians believe this about themselves) than to Hell (only roughly 2% of Christians believe this about themselves--from which we can conclude that Hell is for other people). [These statistics are documented in Hood, Hill, and Spilka, The Psychology of Religion: An Empirical Approach, 4th ed., and they are approximated here.]