I never asked you to prove that naturalism is true because you’re right it is unreasonable to think that you could prove that it is true to all rational people. What I asked you is why you think that the probability that naturalism is true is nearly 100% (although I’m also asking you think why it’s even plausible). This arose out of our conversation three posts back where I responded to your argument that the probability that God exists is zero almost surely by creating an inference to the best explanation argument where I showed that, “Given our background knowledge about the state of the world, God is the best explanation for motion in the universe; the finely tuned universe and everything in it; the existence of objective morals and duties; and consciousness.” The argument showed that theism is highly probable while naturalism is implausible to highly implausible, and you didn’t even try to refute the argument. That would have been fine if it ended there, but you’re still acting like God’s probability is essentially zero while the probability of naturalism is essentially 100% without defending the extraordinary high probability you place on naturalism.
I think that you are a conflating the concepts of atheism and naturalism. I think that the definition of naturalism that you presented is pretty good, but you don’t seem to realize that naturalism is a positive world view that needs to be argued for just like Christianity, Islam and pantheism. Naturalism is not a negative view like atheism which says that God doesn’t exist. Naturalism makes the very bold claim that the universe and everything in it arose from naturalistic causes. So, when I ask you to defend why you think that naturalism is very highly probable or even just plausible I’m not asking you to prove that supernaturalism is false, I’m asking you why you why any rational person should think that it is likely that the universe and everything in can be explained through naturalistic causes.
The Implausibility of Naturalism:
To help you see why a theist (or really anyone who follows where reason leads them) finds naturalism so implausible I’ve created a dialogue between Bob and Dan to illustrate my point:
Bob: “I have some amazing news. Some experts have told me that my great^20 grandfather was not born; he just existed as a brute fact. So, the beginning of my family began with my great^20 grandfather who fathered my great^19 grandfather and eventually my father fathered me.”
Dan: “Wait a minute, Bob, what you’re saying doesn’t make any sense. We all know that people don’t just exist as brute facts—people are caused to come into being by their parents. Why should I believe your story? Why is your great^20 grandfather existence just a brute fact while everyone is born from their parents?”
Bob: “Well, my great grandfather is an exception. It’s the only way that the experts could think of to explaining how my family came to be, so the existence of my great^20 grandfather has to be a brute fact.”
Dan: “Hmm, it sounds like you’re engaging in special pleading.”
Bob: “Oh no, just because we see that things in the universe have a cause doesn’t mean that everything has a cause. I mean look at subatomic particles they’re popping into and out of existence all the time.”
Dan: “That’s not really true, just because we can’t KNOW with exact certainty where a given subatomic particle will be at any point it doesn’t follow that the particle is popping into existence uncaused out of nothing. David Albert wrote, ‘Relativistic-quantum-field-theoretical vacuum states — no less than giraffes or refrigerators or solar systems — are particular arrangements of elementary physical stuff. The true relativistic-quantum-field-theoretical equivalent to there not being any physical stuff at all isn’t this or that particular arrangement of the fields — what it is (obviously, and ineluctably, and on the contrary) is the simple absence of the fields! The fact that some arrangements of fields happen to correspond to the existence of particles and some don’t is not a whit more mysterious than the fact that some of the possible arrangements of my fingers happen to correspond to the existence of a fist and some don’t. And the fact that particles can pop in and out of existence, over time, as those fields rearrange themselves, is not a whit more mysterious than the fact that fists can pop in and out of existence, over time, as my fingers rearrange themselves. And none of these poppings — if you look at them aright — amount to anything even remotely in the neighborhood of a creation from nothing.’ So, subatomic particles are not an exception to the rule that physical things like your great grandfather have a cause. Do you actually have any scientific proof that your great grandfather existed as a brute fact?”
Bob: “No, but look at the success of science, scientists will one day explain how my great grandfather was not born and yet is the cause of my family.”
Dan: “Just because science has successfully explained many things it doesn’t mean that it will explain how your grandfather was not born. Besides, I thought that you said the uncaused existence of your great grandfather was just a brute fact. Brute facts have no explanation.”
Bob: “See, there it is! My great grandfather just exists as a brute fact. Just wait someday science will prove me right.”
Dan: “Well, Bob, that may be so, but I find your story to be wildly improbable.”
So, whether it is the universe itself or subatomic particles and the natural laws I think we should regard the claim that any of these objects exist as brute facts as implausible. There is nothing in the nature of these things that are necessary—all could very conceivably not exist. We also know that everything we see around us has a cause of its existence—even the elements did not exist prior to the big bang.
Add to that the fact that as Alexander Vilenkin has said, "All the evidence we have says that the universe had a beginning." This means that either a) the universe popped into existence uncaused out nothing which is a ridiculous notion, b) contingent objects such as subatomic particles, which just exist as brute facts, are the cause of the universe or c) a necessarily existent, uncaused, immaterial agent caused the universe to come into being. I think that c is by far the most plausible scenario.