Technically speaking beliefs are assumptions about very simple yes or no propositions. Do pigs fly? Yes, no, or maybe so? No. Okay, then. Most of us are in agreement on this question, and so most of our beliefs will conform to the answer: no, pigs don’t fly.
How do we know this? Well, we’ve never seen pigs fly, for one thing. Second of all, they don’t have wings. And we’ve never seen a pig levitate or hover all on its own. So simple observation confirms our assumption, and therefore we know our belief is true.
Almost every belief can reduce down to a yes or no proposition, thus when it comes to unknown propositions since we know that almost all beliefs are probabilistic (I say almost because properly basic beliefs may be exceptions to the rule) we can presume that disputed beliefs, like the question of God or whether or not the universe came from nothing, are either true or false, and therefore in a state of uncertainty must have a probability of being one or the other.
So, taking a guess (or better still an educated guess), we use our experience with things like flying pigs to say, well, I know those aren’t real because I’ve never seen one and they’re not very plausible given what I know about reality.
So what about this God business? Well, I’ve never seen God either, so logically speaking, I probably shouldn’t believe in that one either. God doesn’t match with observed reality, and it seems to me this is why theists like to say God exists outside of reality, but if so then this requires many more unfounded assumptions and so it all seems that much more less likely to be the case.
This realization leads us to demand rather strict demonstrations of proof for low probability beliefs, otherwise, our beliefs simply aren’t warranted, certainly not to the same degree as high probability beliefs are.
Also, there may be certain things we have a lot of evidence for but we still might remain uncertain about. For example, consider questions about love. Is love merely the chemical and biological interplay going on within the brain or is love something more?
Well, in all probability, love seems to be an emotional and physical condition which arises from the goings on in the brain. We have lots of evidence which demonstrates this, but because it seemingly goes against what we typically think love to be, based on our own experiences of it, we are hesitant to say ‘yes, love is merely the chemical reactions happening in the brain’ with any certainty. We feel inclined to say love is something more. But feelings aren’t proofs.
The fact of the matter is, the probability that love is merely a byproduct of goings on in the brain is rather high given what we currently know about the chemistry and biology of love, so we can say ‘yes’ with near certainty that this is what love really is. If we say ‘no, love is something more’, contrary to what the evidence suggests, then we are placing a higher burden of proof on ourselves to demonstrate our belief that love is something more and thereby lessen our chance of being correct.
The higher the burden of proof the more difficult it will be to prove beliefs that defy observation and evidence, thereby forcing us to make more arguments and assumptions in order to defend such beliefs, ultimately leading to a greater probability of being mistaken.
So let’s write it out another way.
Love is merely a chemical process happening in the brain + Lots of evidence which suggests this assumption is correct = high probability of being correct.
Love is something more than mere chemical processes + Little to no evidence = low probability of being correct.
Could it be that the scientists and those of us who think that love is merely a chemical process happening in the brain are all wrong?
Yes, that is a possibility. But because it looks as if we have the higher probability of being right about this assumption, being wrong has a low probability and we won’t fret about it. Needless to say, it is up to those who feel differently to demonstrate their claims convincingly, otherwise we have no reason to go from a high probability assumption to a low probability assumption.
The theist assumes God x 1 = 1 God.
The atheist assumes God x 0 = 0 God.
Also, the testable part of the observation is important, because if it constitutes a reality, we should be able to make the same observation under the same conditions. Unable to do so would suggest that we might be mistaken about what we think we are observing. Religious beliefs of the supernatural variety have, to my knowledge, failed this prerequisite of testability making it seem far less likely that they constitute any given reality.
Positing unjustifiable claims of certitude for un-demonstrated claims which often times defy reason is, I would venture, slightly less rational than reserving one’s conclusions until convincing evidence is forthcoming.
I’ll be the first to admit, however, that atheists could be wrong. But if we atheists are wrong, then common sense dictates that it should be quite easy for theists to provide undeniable evidence for the existence of God, and atheists would happily change their minds accordingly. But this clearly hasn’t happened.
Could all atheists be deluded in the same way we claim believers are? No. Why not? Because our assumptions match with observation. So we’re not deluding ourselves to the truth of the matter.
As with the above example of love, the question becomes what convincing reasons do atheists have for going from a high probability assumption to a low probability assumption with regard to their belief?
Atheism: God is not something which exists + Lots of evidence, or rather lack thereof, which suggests this assumption is correct = high probability of being correct.
Theism: God is something which exists + Little to no evidence (matches with atheists level of evidence, or rather lack thereof) = low probability of being correct.
The answer is there are no convincing reasons to compel us atheists to go from a high probability to a low probability belief assumption, otherwise there wouldn’t be such a thing as atheists. Therefore atheism remains the more reasonable position.
Atheists do not pretend to know more than they possibly can. They have no evidence, so their belief reflects this. Theists think they have ample evidence, but they continually fail to meet the burden of proof yet continue to pretend to know with certainty the things they have no proof for, therefore the theist position is less rational.