If God doesn’t exist, and all that exists are natural laws in a brute sense, it seems that the number of possible configurations of the world are tiny compared to the number of possible configurations if god exists.

If god exists, he could create a universe completely hospitable to life, completely lethal to life, a universe full of fairies, demons, goblins, or any of an infinite number of other beings and objects that you can think of. Planets could be squares instead of spheres, the moon could be made of cheese, and we could all be born 70 feet tall or have minds that don’t need brains, etc etc. The possibilities seem endless.

If god doesn’t exist, then reality seems constrained by whatever laws happen to exist. In other words, the probability of a particular configuration being constrained by natural laws seems very high given no god, but very low given god. God wouldn’t need to set up laws in the first place.

It is interesting that this kind of argument can essentially reverse many of the contemporary arguments for theism. For example, a common theistic argument is that if certain parameters were changed by even a small amount, life would not exist. Because this is very improbable, a designer is a better explanation. However, if a designer existed, he wouldn’t need to fine tune life. He wouldn’t need to spend billions of years of time just to create an earth hospitable to life and then spend another billions of years for life to evolve for humans to exist. Yet given no god, that seems to be the only way for life to arise. But given no constraints by an all powerful God, life could have arisen in any of an infinite number of ways imaginable.

What is this kind of argument called? Is there a notion of this in philosophy?

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    Er... reality is not "constrained by laws". The so-called laws formalise observations made by humans, who do not control reality. They are statements about its behaviour: not what it is or is not permitted to do, but what we expect or predict it to do. Commented Jul 18, 2023 at 17:44
  • How is that an argument against reality being constrained by laws? If it was constrained by laws, we would expect consistent observations obeying those laws to take place.
    – user62907
    Commented Jul 18, 2023 at 17:47
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    It seems that what you’re trying to get at is that laws are based on experiments that are based on inductive premises. Sure, one cannot prove that reality in the next second will not consist of atoms and the planets will not move around other planets in certain predictable ways and instead have the entire universe turn to cheese. But do you really believe that? If not, “Let us not pretend to doubt in philosophy what we do not doubt in our hearts.”
    – user62907
    Commented Jul 18, 2023 at 17:49
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    Regarding the post's last full paragraph, about design. Douglas Adams would mimic a puddle with body language, saying "This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!" Commented Jul 18, 2023 at 18:02
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    @AgentSmith: That is very vague.
    – CriglCragl
    Commented Jul 20, 2023 at 8:30

5 Answers 5


This is a straightforward Bayesian argument. Let H be the hypothesis that God exists, and let O be the sequence of all evidence humanity has ever observed.

P(H|O) = P(O|H) P(H)/P(O)

P(O|H) will be low if H could produce many possible sequences of observations, because the probability mass will be spread thin among all those other sequences of observations. The more "focused" H is towards just exactly the observations actually observed, excluding other observations, the higher P(O|H) will be.

So, yes, if God could have produced any of a huge variety of different universes, then the probability mass for P(O|H) will be spread among many different sequences of observations O, one for each possible universe God could have created, and as a consequence P(H|O) will be low.

  • This misses the anthropic point that we are not in a position to observe all the possible universes that God could have created; we can only observe the universe we are actually in. We have no idea how big the space of possibilities is, or what probability distribution applies to it. Nor do we know, for possible universes other than ours, whether there are observers like us who are making observations like ours.
    – Bumble
    Commented Jul 20, 2023 at 14:07
  • @Bumble But we may still suppose that the set of possible universes God could have created that sentient beings are in a position to observe, is also very large, larger than the set of possible universes that could be created by laws of physics. Because, as the OP mentions, an omnipotent God is not constrained to setting up initial conditions and letting things evolve. He could do that, or could instead directly create a modern universe with sentient beings in any way he likes, without needing anything to conform to simple laws of physics. Crystal spheres are an option, for example.
    – causative
    Commented Jul 20, 2023 at 16:02
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    I don't see any reason to suppose that the set of possible universes is any greater or less depending on whether gods exist. We are using the word 'possible' here in such a general way that we have to allow that anything is possible. Unless you assume that a universe without gods must have laws similar to our own, there are no constraints on what is possible, and I don't see any reason to make such an assumption.
    – Bumble
    Commented Jul 20, 2023 at 17:29
  • @Bumble An omnipotent God would be capable of creating any religious or fantasy fictional universe humans have ever imagined, in addition to all of the universes governed by mathematical laws that physicists study. So it's a strictly larger space. "We have no idea...what probability distribution applies to it"- in the absence of an idea about the probability distribution, it's appropriate to use a uniform distribution or a minimum-description-length distribution. Bayesian inference only concerns our subjective credences; we aren't required to know whatever distribution is in the mind of God.
    – causative
    Commented Jul 20, 2023 at 17:30
  • @Bumble Also, it's not a question of "God vs. all universes creatable by simple mathematical rules" - where God still comes out behind in the P(O|H) term, because God could create any universe creatable by simple mathematical rules, or could create any other kinds of universes - it's a question of "God vs. the specific kinds of mathematical rules that physicists consider plausible in this universe," and the probability mass of those specific mathematical rules is even more tightly focused on just this kind of universe, so the God P(O|H) term has even more trouble by comparison.
    – causative
    Commented Jul 20, 2023 at 17:33

The laws don't constrain what can happen. The laws only describe what has happened and what is likely to happen.

It is the events happened that constrain what could happen next.

In the beginning of the Universe nothing had happened yet, there were no constraints, everything was possible. When something happened, everything else was no longer possible. The next event has to be a causal effect of the first event. That constrains the possibilities of what the next event could be. And so on.

Every cause has an infinite number of possible effects. An electron in an atom drops on a lower energy orbital (cause) and emits a photon (effect). But the direction where the photon goes is completely random, only one out of infinite number of possible directions is actualized. That constrains the number of possible futures, only those caused by the photon going to that direction are possible.

This is no argument against or for God. This is just a description of how events are caused and constrained. You can believe that probabilistic quantum events are not random, but instead controlled by God, but that is just a trick to make religion compatible with science.


The first question you need to ask is what makes the laws? If randomness makes the laws, then there is no limit. The random rules which create stability will survive longer, obviously.

So this answers part of your question.

The other thing is that if GOD exists, then s/he must constrain the universe to that which preserves the order of the universe (the "good" side) and separate that which hurts that order (the "evil" side). So this alone will reduce the number of universes.


If there is a god and if it is an unconstrained god, any world other than this in which we found ourselves would still represent just one of infinite possibilities available to god. An infinite number of those possible worlds would presumably have phenomena which appeared to its human inhabitants as 'natural laws', would involve lengthy pre-human histories just like ours, and would also suffer from divine hiddenness. And regardless of what kind of world was created, if God maintained hidden, we would remain at a loss as to what motivated his design and would remain therefore unable to infer anything from any of the world's attributes; unable to determine whether or not design had played a role at all.

Whichever world in which we found ourselves would always seem incredibly 'unlikely'. We would still find ourselves in one particular world with no reason to account for why the world was created in that particular way.

From this perspective, it is difficult to see how an argument from unconstrained possibilities might be successful.


However, if a designer existed, he wouldn’t need to fine tune life.

There is no common definition of creator gods or their powers and limitations.

Supernatural designers as gods of the gaps require no omnipotence to fill some gap.

But if one believes any part of the universe or history is impossible without some supernatural power, no probability argument can make no god more likely than a god.

Even for an assumed omnipotent power, it is invalid to say this power cannot exist because it refrained from doing what appears most efficient or logical. Such reasoning is easily swept away by any variant of "god works in mysterious ways". Inconsistent behavior is no obstacle to godhood, it even renders the whole narrative more interesting, with the cultist spending time in speculating what mysterious reasons their gods had to NOT do the obvious thing.

In the same sense the relative absence of miracles (unless you want to count the love as a miracle) in modern times does not mean nothing supernatural ever existed, a single historical miracle is enough as evidence of something supernatural having existed at least once.

However, assuming ignorance of whether any miracle ever happened or was ever required: the more knowledge gaps a person has, the more motivation there is to believe in a god of the gaps. Knowing laws of nature which act without plan or purpose and observing a universe that follows such laws removes the gaps and the need for gods of the gaps.

  • The argument is not that that kind of god cannot exist. The argument is that there are an infinite number of gods you can think of who can do things in an infinite number of ways. But the ways in which things are done without god are extremely limited given physical laws. So it seems more probable to just assume no god
    – user62907
    Commented Jul 18, 2023 at 23:06
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    No, this just makes a god that is limited or otherwise self-restraining more probable than an omnipotent god focused on fastest results. It does not have enough weight to make atheism more logical.
    – tkruse
    Commented Jul 19, 2023 at 6:33

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