2
  1. Something whose existence is impossible cannot be conceived in the mind.
  2. Let's make an assumption that there is no God. Since it will be eternal by definition, it did not exist in the past or in the future, and cannot exist. That is, its existence becomes impossible. Since it is impossible, it should not be conceived in the mind.
  3. The Presence of God can be conceived in the mind. There is nothing contrary to logic.
  4. But according to premisses 1 and 2, God must have been something unimaginable and illogical in his extinction.
  5. So the assumption in premise 2 was wrong. So the non-existence of God was a false assumption.
  6. Then there is God.

What do you think of this argument?

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  • 5
    @TankutBeygu, the existence of God is one of the major philosophical questions. It is perfectly appropriate in this group. Aug 3 at 20:49
  • 15
    "Something whose existence is impossible cannot be conceived in the mind." Is that really true? Take an unsolved problem in mathematics--for example, no one knows whether Goldbach's conjecture is true, and it seems as if we can conceive of the idea of "an even integer greater than two which cannot be expressed as the sum of two primes". But if the conjecture turns out to be true then we will retrospectively deem that idea "impossible". If you would say this is not a counterexample, is it because you think we can't really "conceive" this?
    – Hypnosifl
    Aug 3 at 21:10
  • 6
    There's simply no reason to believe the 1st premise. Do you also believe that everything you can think of is possible?
    – D. Halsey
    Aug 3 at 22:02
  • 8
    I can conceive of One Punch Man getting kicked to the moon and jumping back to Earth, yet it is impossible. The premise 1 needs a bit of reworking. 3 also has problems. I see lots of logical problems with the idea of a disembodied mind like God is supposed to be.
    – armand
    Aug 3 at 23:03
  • 3
    The lemma in point 2 also seems flawed. I don't see how the premise that if God exists then he is eternal supports the conclusion that if God does not exist now then his existence is impossible. I think you are conflating two different things: that it is possible for him to exist (and therefore always to have existed, per your characterization that he is eternal), and that it is possible for him to come into existence in the future, supposing he does not exist now. Aug 4 at 5:07

10 Answers 10

4

Your point 2 is a poorly constructed argument that if God does not exist, it is impossible for God to exist.

This borders on the silly. All sorts of things are possible that do not in fact exist. For example, there has never been any beer in my refrigerator. Yet such cold beer is clearly a possibility.

"God is impossible ==> God does not exist" is a valid implication, but its converse, "God does not exist ==> God is impossible" does not logically follow.

St. Anselm and Descartes both advanced similar arguments, concluding that if God exists, then God exists necessarily. From this you could reasonably conclude that if God does not exist, then God cannot possibly exist. However, both their arguments have been heavily criticized and are not universally accepted.

Also, neither of those worthies ever attempted to confuse the issue by claiming that "eternal existence" is a special case of "existence" that needs to be argued separately.

4
  • It follows for a god that is eternal! Aug 4 at 13:50
  • It is trying to say: if there is no God now, there never will be. If there would be a God in the future, by the nature of God, it would have always existed, including now.
    – user253751
    Aug 4 at 14:30
  • You, and OP, are confusing the issue by trying to claim that "eternal existence" is a special case of "existence" that needs to be argued separately. This is what makes the argument "poorly constructed". Aug 4 at 15:37
  • "If God is possible then God exists" is one of commonly discussed arguments. Its premises (assumptions about God and modal logic) can be disputed, but it need not be silly or poorly constructed. Regardless of its merits, "all sorts of things" do not have properties ascribed to God, so it is not at all surprising that an argument might go through for God but not for cold beer, or something else. 2 is the only even number for which a primality argument would go through, for example.
    – Conifold
    Aug 5 at 0:58
19

Let us consider the being named Hpf. Like God, Hpf is eternal by definition. Hpf created the universe and will destroy it on Monday, August 9, 2021.

  1. Something whose existence is impossible cannot be conceived in the mind.
  2. Let's make an assumption that there is no Hpf. Since it will be eternal by definition, it did not exist in the past or in the future, and cannot exist. That is, its existence becomes impossible. Since it is impossible, it should not be conceived in the mind.
  3. The Presence of Hpf can be conceived in the mind. There is nothing contrary to logic.
  4. But according to premises 1 and 2, Hpf must have been something unimaginable and illogical in his extinction.
  5. So the assumption in premise 2 was wrong. So the non-existence of Hpf was a false assumption.
  6. Then there is Hpf.

Too bad for the universe! Better cancel your plans for next Tuesday.


So, now we've moved on from "Is this argument correct?" If it was correct, it would prove the existence of both God and Hpf. The question is now, "We know the argument is flawed, so where is the flaw?"

One flaw is in premise 1, in the concept of "impossible" or "possible." You haven't rigorously described what this concept means. We often use the word "impossible" to describe propositions that we've ruled out by certain methods. But which methods are you referring to in this case?

If something is "impossible" does that mean

  • It's something we can't imagine, as in premise 1?

Or does it mean

  • It's something that did not exist in the past or future, as in premise 2?

So to sum up, it's an equivocation fallacy over the word "possible" or "impossible."

6
  • This answer is not compelling. The characteristic that Hpf is going to destroy the universe on Monday is contingent, while the argument you are responding to is trying to exploit God's necessary properties. Aug 4 at 0:27
  • 20
    @DavidGudeman no, it is a necessary attribute of Hpf that he will destroy the universe on Aug 9, 2021. God is loving, Hpf is inherently Aug92021UniverseDestroying. Hpf would not be Hpf without this attribute.
    – causative
    Aug 4 at 0:45
  • Only OP can really clarify what they meant, but I read the question as saying something whose existence is impossible (using some definition of impossible) implies that it cannot be imagined. To treat premise 1 as a definition or proof of impossibility would just turn the argument into a logical mess (where you can just directly conclude that God exists because we can conceive of him), whereas treating premise 1 as implication just gives us a coherent argument containing 1 or more faulty assertions, definitions and conclusions that should be easy to refute.
    – NotThatGuy
    Aug 4 at 11:47
  • Too bad for proposition 1 ;-). Aug 4 at 13:52
  • This answer is just exploiting the fact that the OPs argument is really for a Supreme Being, not specifically God. Aug 4 at 14:03
8

People in the answers seem to focus on premise 2 but I'm having an even bigger problem with premise 1:

Something whose existence is impossible cannot be conceived in the mind.

We can definitely conceive impossible things in our mind. People have been able to imagine a 4 dimensional cube even though it's "impossible" according to our eyes.

You could say hypercubes are still possible in the real world even though we can't perceive them so take the Ether theory for example: at some point in the past, we though space wasn't empty at all, to the greatest scientist of the time it was completely filled with some weird material called Ether. Tens if not hundreds of brilliant minds created this theory we now know is completely impossible; ergo, we can definitely imagine impossible things.

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  • 2
    ...or pretty much everything in speculative fiction. We know that lots of things in Lord of the Rings are impossible, and yet we can conceive them. It's called "suspension of disbelieve".
    – Philipp
    Aug 4 at 9:57
  • I meant logically impossible things. Can we imagine a circular square? Aug 4 at 12:00
  • @anignorantman Yes, I can certainly imagine a circular square (one that, impossibly, has no corners and yet has exactly 4 corners). I can't imagine it in great detail (for example, I can't imagine what it would actually look like), but I can certainly imagine it. Aug 4 at 12:54
  • 2
    @anignorantman can you completely understand an all-seeing, omnipotent and perfect god? Can you fully explain it? If you wanted to with enough resources, could you create one? Not understanding something completely is not the same as "inconceivable"
    – Tzig
    Aug 4 at 13:03
  • 2
    Importantly we can conceive a Hpf! Aug 4 at 13:54
2

"... Since it will be eternal by definition, it did not exist in the past or in the future, and cannot exist."

As you say, since it exists outside of human cognition it cannot be said to exist - according to human cognition. It is effectively nothing - like the noumenal - adding to the mystery of the concept of nothing.

Unless you can intuitively connect to the eternal, you are stuck.

Nevertheless, your settling of the definition of God is another matter. For example, do you define God as noumenal or extra-noumenal (purely conceptual)? Or perhaps they are they indistinguishable.

2

What do you think of this argument?

I think it is pretty easily dismantled by simple logic, not theology. Since logic is in the purview of philosophy, you're quite on-topic here.

The fallacy of your argument is that you have not only one assumption, but that you have two:

  • Assumption A: "God does not exist."
  • Assumption B: "Something that is impossible cannot be conceived of."

From these two assumptions, you have deduced a contradiction. This allows you to say that (A and B) is false, or equivalently, that (A is false) or (B is false) or (both A as well as B are false) to spell it out as verbatim as possible.

Specifically, from (A and B) is false you can not deduce that A is false; but this is what your argument is erroneously doing.

So to make your argument hold tight, you have to prove that your assumption "Something that is impossible cannot be conceived of by the mind." is in fact true. It is not enough to say that your mind cannot do it, you must prove that every mind cannot do it.

(Note that there may be further errors, even if you manage to solve this first one.)

N.B.: As mentioned in the comments, part of the problem with the assumption is that it is unclear what "impossible" means. If OP wants to make the argument watertight, then this needs to be defined (and then the assumption may or may not be self-evident; and the rest of the argument will need to be checked again to verify that the logical conclusions follow from it, and so on). The TLDR of this answer is that it's too complicated/complex to simply say "it's true".

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  • 1
    It is true that something that's impossible can't be conceived of, in the sense that we can't model it. So that assumption is perfectly valid. The converse is that if we can model God, God can't be logically impossible. The real problem is the argument changes the definition of "impossible" between points 1 and 2. So it's a red herring that assuming God doesn't exist makes it "impossible" for God to exist.
    – MichaelS
    Aug 4 at 13:13
  • 1
    @MichaelS What makes you think that we cannot model impossible things? I'm tempted to say that already that statement invalidates itself! (Also, we can model Hpf.) Aug 4 at 13:57
  • @Peter-ReinstateMonica I have to agree with the other answers saying there is equivocation surrounding the word "impossible". One use refers to a logical inconsistency, like a furiously sleeping colourless green idea. The other use refers to something that will never exist, like faster-than-light travel.
    – user253751
    Aug 4 at 14:33
  • @MichaelS et al, the onus is on the person that wants to use above argument to show that the impossible-conceive assumption holds. No matter whether it's true or false, it is too complicated (as witnessed by the answers and comments here) to simply say "it's true". That's the point of my answer. I'll add a sentence to it to make that clear.
    – AnoE
    Aug 4 at 14:41
  • @user253751 If I'm not mistaken, you just conceived of a furiously sleeping colourless green idea. Aug 5 at 10:22
1

By this logic, all other gods are real too. The Monotheistic gods say there can be no other gods and there is only one true god. You're still left with the dilemma of making a choice: believing it or not.

8
  • 1
    This answer is false. Not to endorse the argument (which I consider seriously flawed), but it relies on theological concepts which don't fit polytheism. Aug 4 at 0:23
  • 4
    It's not false, but it is flawed, not by own doing, but by the way the question was asked. You're also conflating my argument with your beliefs of what polytheistic religions believe and I don't appreciate that.
    – Jbh
    Aug 4 at 1:14
  • @Jbh: The argument presumes things like "God is eternal", which doesn't fit with at least some polytheistic beliefs. I highly doubt David meant there is no possible polytheistic religion for which the argument's presumptions are still valid. Also, this answer doesn't actually address the question in a particularly meaningful way.
    – MichaelS
    Aug 4 at 13:17
  • @MichaelS. I answered the question in the most straight forward way. I don't understand why this site in particular has to answer with ONLY bloated replies. I answered the spirit of the question within the parameters set by OP. His logic boils down to a singularity of choice, he can believe his mind or not, his construct of God is built on the axiom of his imagination, it's in his head only, he has not seen God, he has no real proof, it's in his head. Since he has not seen God and has no proof, the choice is: Does he believe in HIS IDEA of God or not.
    – Jbh
    Aug 4 at 14:23
  • @Jbh: The point of the original argument is an attempted proof that a particular definition of "god" must exist. If we can prove that such a being must exist, it's irrelevant whether you or I or anyone else believes. Proof is proof. But the argument is flawed. It proves nothing. Your answer basically boils down to "nuh-uh!" instead of pointing out the specific flaws in the argument.
    – MichaelS
    Aug 14 at 5:33
0

The problem is you've changed the definition of "impossible" between points 1 and 2, making your second claim in point 2 wrong.

  1. Something whose existence is impossible cannot be conceived in the mind.

    Here, you're talking about something that's logically impossible.

    The converse way of looking at it, is if I can conceive of something, like faster than light spaceships, it's "possible" in the sense that I could, in principle, make a simulation with it, given a sufficiently advanced computer. If it's possible in a simulation, there could always be some naturally-occurring universe, perhaps even our own, in which it's possible.

    Here, "conceiving" of something must mean conceiving a solution, not just a problem. Like creating a pattern of events in my mind where A leads to B, C to D, etc. As long as it's self-consistent, it doesn't matter how bizarre it might be in the real world.

    It is not true that any problem that's conceived automatically has a logically-possible solution. So even though we can "conceive of" an omnipotent being who can create a rock that the being cannot itself pick up, it doesn't make that being logically possible.

  2. (a) Let's make an assumption that there is no God. Since it will be eternal by definition, it did not exist in the past or in the future, and cannot exist. That is, its existence becomes impossible.

    Here, you're talking about something that's "not possible" because it happens to not exist in our universe. It's not "impossible" in the sense that it couldn't possibly be true in any universe.

    Going with the simulation idea, in the video game World of Warcraft, there are no Mandalorian bounty hunters (from the Star Wars franchise). So it's impossible to find one in that game. But the developers could do it if they chose (and, ideally, had copyright permission), so it's not logically impossible, just impossible in practice.

  3. (2b) Since it is impossible, it should not be conceived in the mind. (This should probably be a separate point, not mashed into point 2.)

    This claim is invalid, because the "impossible" definition in point 1 is different from the "impossible" definition in point 2.

Side problem: in your point 3, you say that God is logically consistent. This is only true for some definitions of God. So you have to be careful to not presume that the logical possibility of one definition of God automatically means any other definition of God is also possible.

Likewise, even if we can conclusively prove a particular definition of God is impossible, it doesn't automatically invalidate all other definitions of God.

So even if your argument was valid, it would only be valid for definitions of God that are logically consistent.

5
  • Your argument Here, "conceiving" of something must mean conceiving a solution, not just a problem. Like creating a pattern of events in my mind where A leads to B, C to D, etc. As long as it's self-consistent, it doesn't matter how bizarre it might be in the real world is circular reasoning. If you make logical consistency a condition (you demand "self-consistent solutions, not contradictory problems") it is not surprising that we cannot conceive logical impossibilities: That was your condition! But we surely can think illogical thoughts -- the world is full of them. Aug 17 at 1:31
  • Anything that can be modeled, like a computer simulation, is hypothetically possible is plain nonsense. (1) You are shifting the goal posts: Computers enforce higher logical consistency on a small scale than our minds -- used in the OP's argument! -- which are wrong and illogical all the time. (2) Even so, nothing keeps me from programming impossibilities. Kinetic systems losing energy to nowhere, temperatures going below 0K, and yes, FTL, which leads to paradoxes. Impossible. (3) Simulations are not complete. Those details or model externalities can hide subtle impossibilities, too. Aug 17 at 8:30
  • There's no difference between logic running on a computer and logic checked by hand: Yes there is, part of why Lemma 1 is wrong. The computer (i.e., programs executed on it) applies boolean algebra and other types of "computational mechanics" in a near perfect fashion, which makes it immune to certain classes of mistakes that I make all the time. I can be wrong and inconsistent already on a very trivial level. My napkin calculation is wrong, my logical inferences are flawed, and I do not realize it. This is the human modus operandi of all of us, which is one reason Lemma 1 is nonsense. Aug 17 at 10:20
  • There is your circular reasoning again, isn't it? I conceive of something impossible because of a mistake and you say "oh, that doesn't count, it is inconsistent!" Yes it is: I conceived of something inconsistent and therefore impossible, trivially violating Lemma 1. Case closed. Also, of course, more interesting are the less trivial inconsistencies that neither you nor me catch. Do you think that is impossible? There are even flaws in mathematical proofs that are caught only later. Generally spoken, flawed thinking is much easier and more common than stringent thinking. Aug 17 at 10:50
  • Let us continue this discussion in chat.
    – MichaelS
    Aug 17 at 11:15
0

Let's make an assumption that there is no God. Since it will be eternal by definition, it did not exist in the past or in the future, and cannot exist.

This is a wrong: suppose there is no God, there has never been a God, and there will never be a God, that does still not mean that a God can not exist. Maybe it is perfectly possible that a God exists, but we just happen to live in a universe where there is no God.

Example: there has never been a Roman Emperor named "Cicerus", and there will never be one. Does this mean that it is impossible? No, it just did not happen.

0

The Penrose staircase is a compelling counterexample to your claim that something that's impossible can't be conceived of - it's impossible, but it can be drawn and even filmed (it appeared multiple times in the movie Inception).

Your basic argument conflates "impossible" and "does not exist." The assumption that God doesn't exist does not imply that His existence is impossible. The fact that there will never be a configuration of the universe in which something is the case does not mean that there is no possible configuration of the universe in which that happened.

Logical possibility is a fairly low bar that specifically cannot be derived from any actual state of the universe (past, present, or future). Dumb example: I work as an engineer, but at one point I had planned to become a medical doctor. It's completely logically possible that I would have become a doctor instead of an engineer, even though that's not what actually happened. There is a coherent configuration of the universe in which I am currently a doctor, so it's logically possible.

Also, I don't agree that the definition of God necessarily entails Him being eternal. That being said, the fact that He doesn't exist now does not imply that He never existed or will never exist in the future. Zeus and many of the other Greek deities, for example, were immortal but not eternal (they had a definite point where they came into existence). You can also easily imagine a deity that was neither immortal nor eternal, or one that had no beginning but has an end.

-2

Your Lemma 1 is wrong, which shows that it is wrong.

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  • 1
    But why is Lemma 1 wrong?
    – Philipp
    Aug 4 at 14:07
  • @Philipp Isn't that obvious? Because we can easily conceive of nonsense like Lemma 1! Also, because we can conceive of Hpf. I think, by the way, that "why" is hard to answer -- I merely answered "how". Aug 4 at 14:11
  • 3
    Your answer should not rely on other answers to fill the holes in it. And if it would be "obviously" wrong to OP, he would not have wrote it. So an answer to this question should explain what exactly is wrong about this lemma.
    – Philipp
    Aug 4 at 14:16
  • @Philipp On a more serious note it's hard to understand why the OP had this crazy idea at all: Probably almost everything we "conceive" -- our model of the world -- is, strictly spoken, impossible. We don't know the underlying reality really, and what we know, we ignore. For example, until the 20th century people thought that interaction (by light or gravity) between distant objects is instantaneous, which we now "know" to be impossible. Most likely the world models we conceive of today are equally impossible because we are just half-blind ants in the universe. Aug 4 at 14:17
  • 1
    @Philipp In our daily thinking we certainly don't conceive world models under the constraints of general relativity, or quantum mechanics. We think that each object has their fix location in space and time which is not only wrong but a categorical error. It is utterly impossible for fundamental reasons to assign these everyday properties to anything. And that is in a domain where we try to make true models. In fiction we try to be creative and come up with impossible things all the time. How can one seriously write down an obvious absurdity like Lemma 1? Aug 4 at 14:23

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