Justin has posted a new response to me on his blog and this is my response to him (as always, his words are in italics):
[S]ubjective experience is a type of evidence, in which case I'm defending the position that the posterior probability that God exists given a religious experience is high. Afterwords, that degree of belief becomes the new prior. Either way the question is the same: is personal subjective experience a rational basis for a belief?
This would lead me back to my original statement: Your reasoning is that if the Christian God exists, then we are warranted in trusting our inner experience of God and of believing that muslims and atheist's inner experience are due to their hardness of heart, demons, or something else. But this reasoning begs the issue at hand: What we want to know is whether or not Christianity is true, not conditional statements about it possibly being true. We cannot begin by assuming that Christianity is or is not true. We have to begin with a more agnostic stance, because that is really where we are. We don't know if the Christian God exists, but subjective experience of him is not good evidence because people's emotional, subjective experiences are usually wrong, as is evidence by the followers of Ras Tafari, the born materialists (if you're a theist), the Hindus, Buddhists, Muslims, etc.
Justin responds to this as follows:
Christians do not begin by assuming that Christianity is true. Rather, they begin by assuming that their personal experiences are generally true. That forms the basis for believe as explained at the start of this post. The burden of proof falls on atheists to provide evidence that religious experiences are a delusion. Simply applying the principles of indifference does not work. When I see a tree I should not have to be indifferent between 'there is a tree' and 'my senses are deluded and there is no tree.' If on the other hand, a skeptic can show that the tree is just a giant cardboard cutout then I will reject the evidence of my senses. But even so, the burden of proof falls on atheists, not Christians. Faith is rational without evidence.
Seeing a tree is not quite the same as feeling the 'inner witness' of the Holy Spirit. For one thing, we can all see the tree. Even if someone was raised in a place where there were no trees, you could still show them a tree (though they would not know what to call it). Furthermore, dowsers, psychics, and alternative medicine gurus often truly believe that they have powers, but we obviously know that they are wrong, so subjective beliefs about objective reality are simply irrelevant and not valid guides to it. I suppose you could say that the psychics, alternative medicine gurus, and dowsers are lying for money, but I don't think that's true. Have a look at "The Enemies of Reason" with Richard Dawkins and see for yourself whether these people are worrying about financial gain (or are insincere). Better yet, take a look at all the studies on placebos that have been done.
The inner witness of the Holy Spirit is not quite like seeing a tree because most people who were not raised Christian do not have it. The cultural context in which someone grows up and lives in almost always predicts what their inner feelings about religion are. And of course most culturally specific beliefs (meaning not held by most human beings the world over, but only in certain cultural contexts), at least the ones concerning religion, are false. The fact is that if you had been raised in India, Saudi Arabia, or Europe (before the 4th Century) you would very probably not have any inner witness of the Holy Spirit. Maybe an inner witness of Allah, or Krishna, or Hercules, or Aesclepius, but almost certainly not the Holy Spirit. Since we can see that subjective feelings about God are strongly correlated with culture, and most cultures have to be wrong, then this type of feeling is not a valid type of evidence for God because it is usually wrong.
Justin has an amazon list in which he wrote the following:
The obvious challenge is that you would then be free to declare anything a properly basic belief. Alvin Plantinga calls this the "Great Pumpkin Objection" in honor of Linus from the cartoon strip. But there is some fine print attached to properly basic beliefs. (1) They must have a truthful origin. Linus does not have a properly basic belief because it is based on his parent's lie. If Christianity really ripped off the ancient mystery religions then it wouldn't be a properly basic belief either. The second criteria is that they cannot contradict other beliefs (properly basic or otherwise). For example, if there is no solution for the problem of evil then Christians would be forced to reject faith in God. In that case the existence of evil contradicts the existence of a loving God.
But Linus does not know that what his parents said was a lie, and since Linus strongly feels that there is a Great Pumpkin, how would he not be justified in believing it by your epistemology?
AIG Busted makes a new argument against the demon. It essentially mirrors the Dawkins/Dennett position against the existence of God – the Demon is too complex to be probable. In the words of Dennett, the Demon is a skyhook, not a crane. I could make a rebuttal and point to the irreducible complexity inherent in both theories of the multiverse. In other words, atheism needs cranes [I think Justin here means 'skyhooks'] too. I see no reason to favor the multiverse over the evil demon on that ground. But I don’t want to get dragged into an evidential debate.
I wouldn't say that the multiverse is a skyhook. Most multiverse theories involve lots of empty space (which in physics, is not quite 'nothing' but is still as simple a something as you can get) or one original universe which makes a few black holes that evolve into other universes. I would consider that incredibly simple.
My subjective personal experience is a perfectly legitimate basis for that belief. We have tons of these beliefs: how much weight I lifted at the gym, whether or not I killed that annoying guy PwnzJ00 in Quake, and whether or not that person in the old beat-up pickup truck let us change lanes.
Again, sense experience is not quite the same as emotional feeling.