Before I continue with the entry proper, I should mention I only wrote this entry because I felt like responding to
this post I read on that blog. However, while I have some interest and ideas about philosophy, I am not a philosopher. This is not an excuse that I be excused from criticism -- I am merely stating that I do not know how to argue formally in philosophy.
So the following is simply my thoughts about the topic, not a proper defense of the evidentialist position -- I leave that to people who actually know their stuff better.
From my viewpoint, the ideas goes something like this:
How do you know?
Knowledge is acquired ultimately through experience. Whenever we say we know something, we mean that we saw, heard, felt, etc (ie, sensed/experienced) that something. Even if the knowledge was acquired from someone else (ie, learnt), that someone experience it first or the chain terminates with someone experiencing it directly.
I say I know the apple is red because I can see that the apple is red. Even if I have never seen apples in my life, but I may still say I know the apple is red because someone who saw the apple told me that it is red.
Note that I am not talking about justified propositions yet. I am merely showing that all knowledge claims is founded through experience. Whenever we answer the question "How do you know that?", we answer with some kind of experience, direct or indirect.
Experience and Evidence
If you experienced something, that something should exist in objective reality in order for you to have experienced it.
This is true regardless of whether your subjective experience was deceptive or not. If you heard a sound, something must have made the sound (vibrations in the air). If the sound was an auditory hallucination, it is still real but not as vibrations in the air but a neurological malfunction.
So, in principle, if a thing exist, and you experienced it in some way, that experience is some kind of evidence.
Forms of Evidence
Evidence comes in many forms and their reliability differ from one form to another. The simplest form of evidence is the entity itself -- and possibly the most powerful evidence for the existence of the apple is to show the apple itself.
We can have a slightly more indirect approach. Let's say we have the apple's peeled skin. We can say we know there was an apple via reasoning that the apple skin must have came from a whole apple originally -- that is unless we know of some method of producing apple skins without apples.
Even more indirectly, we could have no actual physical parts of the apple but, say, photographic evidence of the apple -- providing that there is no forgery. This is indirect observation of the apple.
We could rely on memory and testimony. Someone could have seen the apple sitting in the refrigerator and told you you about it. But just like the other forms of evidence, there are caveats. For the case of memory and perception, we know that human beings are known to misperceive, misremember and miscommunicate. So we adjust the value of such evidence accordingly.
Justified True Beliefs -- Knowledge
If something is real and experienced in some way, then some kind of evidence would be available. If we have sufficient evidence to be certain (high enough, not absolutely), then we can say we know that something is real.
Arguing that evidence is not available for whatever reason is tantamount to saying we don't know that that something is real. Because if we cannot produce evidence, we cannot meaningfully say we know it is real since we can't verify it.
Believing something for which there is insufficient evidence is not prohibited by this position -- it addresses knowledge not mere beliefs. One can believe something to be true without knowing if it is indeed true. With regards to god beliefs, this position is held by agnostic theists -- they believe in god but cannot know for certain it exist.
So jumping straight to the example in the post I was referring to,
While evidentialism certainly does apply to many things, such as deductive beliefs like 10x20=200, which is derived from from more basic beliefs like 1x2=2 and 10x10=100, there are many beliefs which we hold dear to and think are obviously true that we can't show any evidence for.
Take for instance the belief from memory that I had coffee at a nearby Starbucks restaurant this morning. You might go, "Aha! Why can't you just go to the cafe I went to this morning and ask the staff if I indeed had coffee then?"
It's not as simple as you think. Suppose that I did go to the cafe, but none of the staff seems to remember I was there this morning -- which is quite plausible. Suppose also that none of my friends or family members knew -- they were all sound asleep, and I did not check into Foursquare. My iPhone battery had died.
Easy, check your wallet, you may say. But the frustrating thing is, I cannot remember how much was in my wallet before, so there is no other reliable evidence that I did go to Starbucks.
But isn't it absurd for us to question our memories this way? After all, I am frequently right about my memories. But by saying that your particular memory is accurate because, generally, your memories tend to be true, that is a circular argument. Even if we collect a sample size of 1,000 memories (where no external corroborating evidence is available) and claim that 90 percent of them are true, it does nothing for us.
This example demonstrates a major dispute with evidentialism.
Firstly, about memory.
Memory is admissible as evidence. It is just very poor evidence in the hierarchy in light of the other things we know about memory.
It is fine and practical to use just memory to justify beliefs in general but beliefs are only as certain as they can be justified. So beliefs justified purely through memory is weaker than beliefs justified by other forms of evidence. You could claim that it is knowledge but it would be very poorly justified knowledge, ranking so low that it would be close to beliefs, unjustified knowledge.
So if I believe I went to Starbucks purely because I had the memory of that being the case, for practical purposes, good enough. But it still doesn't qualify as knowledge. For that I may need, say a video of me being at Starbucks and perhaps some corroborated eyewitness testimony.
Secondly, isn't it absurd?
Actually, yes, if that it what we're proposing. But it's not. That is why we make a distinction between mundane claims and extraordinary (or simply important) claims.
In a court of law, given the same scenario, you are thought not to have been at Starbucks regardless whether it is true that you went to Starbucks or not, simply because the court only has your word (ie, your memory) and nothing else.
Similarly, the event could be true and you believe it is true, but it will not qualify as knowledge unless you can provide higher standards of evidence. It works somewhat like the burden of proof -- you can believe all you want, but once you try to elevate it to a knowledge claim, you must be able to demonstrate it.
So indeed, it would be absurd to require an investigative report for every piece of memory you have. But for practical purposes, we only do that for important and/or extraordinary claims. However, it does not change the fact that we wish to know something, there should be evidence for it. So if my trip to Starbucks is to be an important point to establish, I must be able to demonstrate it.
Which is why it is seemingly absurd for scientists and atheists alike to demand evidence for God when they themselves hold beliefs they have no proof for.
Why should the methodological rigour of scientific experimentation be applied to the question of God? And assuming that it ought to, then shouldn't evidentialism apply to everything else as well -- an absurd notion nonetheless?
It is absurd in the sense that it seems like hypocrisy and not because evidentialism is false. And this is the important point.
As mentioned before, we don't ask for and probably don't require sufficient evidence for mundane beliefs for practical reasons. But it is, in principle, possible to provide evidence for mundane beliefs -- say videoing every aspect of your life if you so wish to verify.
So the question is not "Why should the methodological rigour of scientific experimentation be applied to the question of God?" since "And assuming that it ought to, then shouldn't evidentialism apply to everything else as well". Because evidentialism does apply to everything else.
The real question is: Is the belief in the existence of god a mundane one? The answer is no as long as you attempt to elevate it to a knowledge claim (which is almost always the case).
So if god is real, actually existent, where is the evidence to justify him when we should be able to find them in principle?