Proving a Universal Negative

by Max Andrews

The question of whether or not one can prove a universal negative usually comes into question for the atheist in proving that God does not exist.  (I’m using atheism in the sense that an atheist believes that God does not exist).  The question is can an atheist prove the non-existence of a being (a universal negative)?  Yes, he can.  Usually you’ll hear arguments against atheism that suggest it’s untenable because it’s impossible to prove a universal negative (that’s really a bad argument, no one should ever use it).

What if I say that there are no tyrannosaurus rex living on earth today?  There are certainly some questions like, “Are there any polka-dotted geese that exist?”  Well, if that may be difficult to disprove universally since I would need exhaustive knowledge of the universe.  So, okay, I cannot disprove that universal claim.  So what now?

It’s actually quite simple to prove a universal negative or the non-existence of anything.  All you would need to do is demonstrate a logical contradiction within the universal claim.  So, for the atheist, I believe his best argument is to demonstrate the logical impossibility of God (to prove a universal negative).  How would he do this?  I don’t know, as a theist I don’t believe any atheist can prove an inherent contradiction in the existence of God, that’s his task, not mine.

12 Responses to “Proving a Universal Negative”

  1. Showing logical contradictions requires a specific definition of god. I think the problem of evil is a fine example of this employing a very conventional and popular definition and providing a strong refutation of it.

    Many conventional definitions of God also incorporate claims that can be contested on empirical grounds. If there is a God, does he answer prayer or punish sin in any meaningful way in the temporal realm? No. A God that incorporates these attributes as an essential part of his definition can therefore be refuted.

    Your insight is a good one: I proposition incorporating a universal positive, once refuted, is in a sense the proof of a universal negative.

    • Hey Jakob! I agree with you in the sense that I believe the problem of evil is your best and strongest argument. I was actually planning on giving that as an example in an upcoming post (so stay tuned!). As far as the issue of hell you raise, that’s not so much an objection to the existence of God but an objection regarding the inerrancy of the Bible (you’ve inspired me for yet another post lol). As you know, I hold to the Anselmian definition of God, and agreed, showing a logical contradiction via the problem of evil is the strongest avenue I believe you have.

      • It’s an objection to the existence of a particular God (the God most Christians call the God of the Bible). I don’t think there can be any such thing as a generically applicable objection to the existence of all potential Gods.

        I eagerly await your post on Anselm’s argument; I definitely plan to devote a post to the issue myself sometime soon.

  2. One fairly common concept of God that could be seen as involving a definitional contradiction is the standard Omniscient, Omnipotent definition (I omit Omnipresent as that property is irrelevant to the contradiction). Yes, this is a fairly common observation that has been made by many writers, but I have not heard a convincing refutation of it (possibly a result of my ignorance rather than such a refutation’s non-existence). Can a god both know everything for certain, and still retain the omnipotence necessary to change its mind about its own future actions, or to change the course of the future in any way?

    As for the problem of evil, this is only a powerful rebuttal of an omniscient, omnipotent, omnipresent, BENEVOLENT entity (yes, yes, this is the concept in which most Theists believe). There is no problem at all in explaining the existence of evil if God is benevolent and NOT omnipotent, or NOT omniscient. Similarly, there is no “problem” if God is not benevolent – evil is easy to account for under these terms.

  3. A perfect being that creates can be seen as a contradiction. If it creates, it must desire to create. If it has desires then it must be lacking. If it is lacking then it is not perfect.

    WLC’s answer is that God didn’t create us for his own sake but for ours. Leaving aside that I don’t think this makes sense – he created something for the sake of the thing that didn’t actually exist yet? – this doesn’t actually solve the problem. If I go to the shop to buy milk, it’s because I want to buy the milk. If I’m buying the milk for my next-door neighbour then I’m still buying the milk because I want to buy it – regardless of whether I’m doing it on behalf of someone else. If God is doing something for our sake, then he’s still doing it because he wants to do it, and so the same problem applies.

  4. Why do you say you can disprove a universal negative? You can’t, it is not possible to prove that god does not exist, but that does not imply that he does. Not knowing something, is not evidence that it is wrong, it is merely evidence that you don’t know everything. Just like the theists who say ‘you atheistic scientists can’t prove everything, that means god did it’. As an atheistic scientist, that deeply offends me for the education in this country, if people actually think that argument is scientific.
    The example I give, is I actually have a deal with god, He loves me you know. From his love, he gave me a great gift; I can fly. I can concentrate very hard, flap my arms, and sour through the air. It is so much fun. It is wonderful! The only problem; he doesn’t want anyone else getting jealous of His love for me, and His wonderful gift. Because of that, he doesn’t let me fly when people can see. That is fine, I like flying at night, cool air, wonderful lights….
    Your task; tell me how you can prove that is wrong? You can’t possibly prove that I do not have the god given ability to fly. That fact does not prove that I actually can fly (which I can, I promise) it merely says you can’t disprove it.
    This is the exact reason we went to war in Iraq; It was impossible for Saddam to prove he did not have WMDs. Just because we have yet to find them, or any evidence of them, does not mean he didnt have them.

    I understand the feelings of wanting to think with enough evidence, with enough facts, you can prove anything. The mathematical fact is you can not prove everything. Math is logic. Logic can not prove everything, but just because logic can’t prove something, doesn’t mean the opposite is true. That is faulty logic.

    • Tell me, are there any four angled triangles in existence?

      • Max – look into the Law of Non-contradiction. if it is TRUE by definition that a triangle has three angles than it can not be true that there are any “TRIANGLES” that would have more or less angles. Up is not down, Blue is not green.

        • How does your reference to the triangle say anything to what I’ve said and cause allusion to me needing to know about that law of logic (it seems like you think I’ve never heard of it…). But actually, Up and Down depend on the reference frame so up and down may be the same thing but are simply semantic devices used within a specified reference frame for direction but outside of the reference frame, etc. it may actually be that up and down have the same direction… Blue and green do share similar properties of electromagnetism but, yes, the wavelengths are different.

  5. Well, this is a bit old, but this is a personal pet peeve of mine, so I have to comment. Brian said:

    “Why do you say you can disprove a universal negative? You can’t,”

    Zero mathematicians and zero logicians agree with you.

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