Faith cannot be rational, but this does not matter. Many things inherent in and/or vital to the human experience cannot be rational. If faith is to be simply dismissed, you need a better reason for doing so than "lack of rationality".
I agree with all of your post except the first sentence.
I do not think this will be a popular post, but still I will try to articulate my disagreement in a readable manner.
People seem to confuse 'rationality' with 'scientifically verifiable' or at least 'based on scientific data'. Maybe this comes from the vantage point that beliefs and opinions not based in science are not rational.
From the standpoint of a logician, I disagree.
Can faith be scientifically tested, proven, or known without doubt: no. But I do not see how that precludes it from being rational. In general, many faiths and forms of belief are exceptionally rational if you accept their base assumptions.
Now that's a big IF. If you do not accept the basic assumptions of the specific faith, it will be forever in your mind 'irrational'. So can faith as a consensus be rational: no, not ever. Can faith be almost perfectly rational from a logic standpoint: absolutely, as long as you accept the base assumptions.
For what it's worth, the base assumption of the (materialist) atheist worldview is that the natural world is a closed system (i.e. no supernatural), from which it follows that science can (at least in theory) describe all of reality. This is a very lightweight assumption, and an easy one to make, but I would point out that it is also not scientifically verifiable, as all scientific data has to be interpreted as being the result of some natural law.
Faith is different from these other things, in that it's still a sort of truth claim.
Fun, beauty, love, etc. are irrational and vital to the human experience. However, they're purely emotional. Basically, they provide the goals which our rational faculties seek to fulfill.
Faith goes beyond this, because it ultimately says, "I believe that this is true." The others are simply "I enjoy this" or "I am compelled to do this" or "this satisfies me", but faith is different because it's fundamentally making an objective claim. And there is every reason to reject that due to irrationality, even if you accept these other things.
Perhaps 'rational' is too broad, as it seems the author means rationally probable, rather than rationally definite - we have "faith" in a large number of things that we don't actually see or know personally, but we have rational reason to believe or more likely to be true than not. If I rationally believe it is probable that a knife is holding will cut the bread I want to eat, this requires little faith because if it doesn't I can just grab another knife. When it comes to believing in something intangible like a religion, rational probability may take an individual to one level of certainty based on their experiences which deny or confirm the implications of that belief. However their faith to act further on those implications may be a matter of faith based on the potential risks. the author writes in the full paper:
A person might have faith in God when it comes to giving weekly donations to the poor but lack faith in God when it comes to allowing himself to be martyred.
Faith is the substance of things hoped for and the evidence of things not yet seen. Even scientific inquiry requires at least a scintilla of faith. One forms a hypothesis with the hopes (but not the certainty) of finding something meaningful at the end of the journey.
When I fall ill and go to the doctor, as opposed to going to medical school, is it rational? Off course it's rational. But that act of leaving my health at the hands of this dude whom the world tells me will get me back to good is essentially faith.
I'm not a very philosophical/bright type, so I may come up shot if someone wanted to take this up philosophically, but at basic level I do think faith is rational. A lot of the inputs for what we consider rational may very well be acts of faith.
There's a huge difference between the colloquial use of the word "faith" and what we know to be an educated guess. Scientific hypotheses are educated guesses. Going to a doctor to treat a medical condition over going to the witchdoctor is also an educated guess.
In both cases, the person making the decision has knowledge about the subject matter and makes it congruent to what he knows. When your doctor makes a decision, it is because of not only his past experience, but the accumulated knowledge of other physicians.
This is entirely different from "I believe that a perfect, omnipotent, omniscient, benevolent creator-god sent his perfect son to die for our sins," because there's no evidence that any of that ever happened.
For clarity, I am what religious people call an atheist. Personally I reject that word because I dint see why we need words to describe people who don't believe in thing that doesn't have any basis in reality. For example, there is no word for people who don't believe in fairies, ghosts, or such like. I find the word "atheist" patronizing and insulting. That said...
If faith is a conscious choice, yes it can be rational.
So, if a person says; "yes that book is full of stuff I want to follow because they believe that it will be a good guiding light for me and I chose to believe that the supernatural being the book insists is real such that it helps to keep me following the rules in the book out of the fear that the super being will judge me", then to me it makes rational sense. Its a rational choice. They do know that in reality is is not real, but they chose to live that way. The choose to engage in faith. Very useful for example for recovering addicts, or people who have faced some trauma.
What I will never understand is people who literally believe a given god and there for religion is absolutely true or real. Worse still is when children are brain washed from birth to believe in such gods.
So, if its a conscious informed choice to have faith, then yes, it can be perfectly rational.
I am reminded of a conversation between the Arch Bishop Of Canterbury and Ricky Gervais. After not long, the Arch Bishop essentially conceded that god, heaven, hell, and so on are really metaphors. Needless to say I, saw the light. Twice actually. I understood the nature of religion, and how damn smart and intelligent comedians are.
My advice, stop using the word faith, and carve the word up into something that means more precisely what you are trying to say.
I'm not sure that choosing to believe arbitrary things due to the consequences of believing those things can be rational. An active choice to believe something without evidence due to the consequences of belief has no effect on the odds that the proposition is true. It's the difference between "I have belief in Thor" and "I believe that belief in Thor is good." Very, very different things, and they are not remotely interchangeable.
A belief that can be demonstrated and tested, because it is inherently an objective phenomenon is better known as a hypothesis.
A belief which has your confidence because of subjective experience that cannot be shared (i.e. if you tried to, everyone would think you were crazy) can be rationally held, though it would be irrational to think you could successfully spread this belief.
A belief which you are terrified of testing against the crucible of reality by making excuses for why there is no evidence (e.g. epiphenomenal dualism, wherein the material plane is observed by the metaphysical plane, but the metaphysical plane never acts at all with the physical plane, and the metaphysical plane not existing would look exactly the same as the metaphysical plane existing) is by definition, fucking nuts. When you are making excuses for a belief about why it should be immune to testing, you are in a very, very deep error state.
I have to agree that faith can be rational. My biggest argument for this how the human psyche works. A person can say they have faith (in some cases even a gut feeling) but what they are experiencing in reality is a sum of what they subconsciously know. The example having faith that your wife is not cheating on you stands behind this point in that subconsciously you know that you know certain things about her day or you knew where she was at certain points. Even religion is in reality just a sum of what collective knowledge you have and whether or not I'm your mind it is collectively enough proof for you to believe.
Faith has and should always means trust in someone or something based on some form of evidence. It is the con men that sells irrational belief as faith. Irrational belief is extremely dangerous. We have hundreds of years of futile wars fought in the name of religion, many conflict today are "faith" based. Reason is the only way we can decided if something is right or wrong, irrational belief as law can only create chaos and/or despotism.
