Nowadays, the most popular argument for atheism looks like this:
It is possible (at least a priori) to explain all facts of the Cosmos as satisfactorily with nature alone as with God
ER: if theory A and theory B do the same job of describing all known facts C, the simplest theory is ALWAYS more likely
God is much more complex than nature
Nature alone is much more likely to be responsible for reality than God
Of course, since neither God nor nature can explain their own existence, ER stipulates that the existence of nature as a brute fact is much more probable than the existence of God as a brute fact.
ER is employed in a huge variety by proponents with diverse worldviews. This is the main reason why most scientists believe that UFO cannot be something otherworldly.
Despite the voluminous literature related to ER, it comes as a surprise that only a few publications deal with its justification. And unlike the expectations of its most enthusiastic proponents, such a demonstration proves a formidable task due to its universal claim to always hold true.
In this entry, I’ll show why I’m under the impression that nobody has been able to prove ER without begging the question in one way or the other.
One common way to argue is by using a reductio ad adsurbum.
Let us consider the following realistic conservation I could have with a UFO denier.
Skeptical Manitoo: „I was really shocked as I learned you believe all this non-senses about flying saucers!“
Lothar’s son: „Actually, this isn’t quite true. I do believe most of them can be traced back to natural or human causes. I’m just undecided about a small minority of them. I consider it possible that something otherworldly might be going on…“
Skeptical Manitoo:„What??? How dare you utter such lunacy before having drunk your third beer? The UFO hypothesis is the most complex one, therefore it is also the most unlikely one!“
Lothar’s son: „And how the hell do you know that, all other things being equal, simpler explanations are always more probable?“
Skeptical Manitoo: „And how do you know otherwise that the traces on the field stem from some wild living things rather than from elves?“ he replied bitterly.
At the point, the skeptics expects me to recognize this is silly indeed, AND that the only way to avoid this madness is by believing ER, so that I’ll end up agreeing with him.
But this is only a pragmatic argument, it has no bearing on the truth of ER whatsoever.
What if I stay stubborn:
Lothar’s son: „I believe your elfic intervention is also within the realm of possibilities, even if it is more complex.“
Skeptical Manitoo: „What? And would you also tolerate the presence of a Flying Spaguetti Monster which has caused the rain shower which fell on us previously?“
Lothar’s son: „„Of course!“
Skeptical Manitoo: „What? And do you also believe in a flying Dick Cheney who threw bombs upon the civilian population in Iraq?“
Reaching this level of insanity, I might very well be tempted to nod in order to escape the ordeal.
But it is important to realize that this whole discussion only shows, at best, a pragmatic MR to be valid.
If there is no INDEPENDENT ground for rejecting the crazy situations my imaginative friend has mentioned, anti-realism seems to be true, which means we can never have any kind of knowledge.
To justify the Epistemological Razor, one clearly needs non-circular arguments which might come from pure philosophical considerations or experimental inferences.
A very commonly used one is the alleged inexorable progress of science towards the simplest explanations.
There are many problems with this argument. The history of science is full of examples of complex theories who were wrongly dismissed because of their lack of parsimony, tough the future vindicated them in the most triumphant way. Continental drift and the reality of ball lightnings are only two examples on a long list.
But let us suppose for the sake of the argument that during OUR ENTIRE history, the simplest theories always proved to be the most likely.
Would this show that ER, as I’ve defined it above, is true? Not at all.
All this would prove is that we live in an universe (or perhaps even ONLY a region of an universe) where things are as simple as possible.
But modern science seems to indicate there exist a gigantic (perhaps even an infinite) number of parallel universes out there. And as Max Tegmark pointed out, these are not only limited to those resulting from chaotic cosmic inflation and string theory, but include as well quantum universes (Everett’s theory) and perhaps even mathematical universes. Simulated universes can certainly be added to this list.
So ultimately the justification of Occam’s razor would look like that:
in our universe, simplest explanations are always the most likely to be true
if it is true in our universe, it is also probably true in the other 10000000000000000000000000000000000…… universes we know very little of
therefore, in the entire reality, simplest explanations are always the most likely to be true.
I hope that most of my readers will realize that premise 2) is an extraordinary claim, an interpolation based on nothing more than wishful thinking.
I know there have been many elegant attempts to ground ER on bayesian considerations. Like philosopher of mathematics Kelly I believe all are hopelessly circular because they smuggle simplicity into their definition of reality.
I’d be glad to learn from my reader if they know ways to justify ER which don’t presuppose the existence of a simple multiverse in the first place.
Finally, I want to point out a further problem one should have using ER against the existence of
The Kalham’s cosmological argument (named after a great Muslim theologian) tries to establish the existence of a transcendence as follows:
Everything that begins to exist has a cause
the universe began to exist
therefore the universe has a cause
Due to the overwhelming experimental and theoretical success of the Big Bang theory, atheist apologists can no longer deny premise 2)
Consequently, they typically deny premise 1), arguing like Jeffrey Jay Lowder that it is not always true.
Lowder agrees it would be absurd to believe something in our universe could pop into existence, and this is the case because all our experience allows us to INDUCTIVELY conclude this is never going to occur. But he also emphasizes that this inference is only valid for things taking place WITHIN our universe, and not outside.
Since the grounds for believing in 1) are limited to our experience in this universe, we’ve no warrant to assert it is generally true.
But this is exactly my point about Occam’s razor or the principle of parsimony.
It might (or not) be true it holds in our universe, but this gives us absolutely no justification for believing it can be applied to transcendental realities (or to rule them out).
So, this was admittedly a very long post, and I hope to receive lots of positive and negative feedbacks!