# William Lane Craig says you can disprove a negative **URL:** \ **Category:** Great Debates\ **Created:** [November 27, 2014, 3:17pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762 "2014-11-27T15:17:43Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Robert163](https://avatars.discourse-cdn.com/v4/letter/r/4af34b/32.png) [@Robert163](https://boards.straightdope.com/u/Robert163)\ **Post date:** [November 27, 2014, 3:17pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/1 "2014-11-27T15:17:43Z")
William Lane Craig says you can disprove a negative. For example, “the are no Lions in Africa” can be disproven. Atheists, agnostics and rationalists use the term “you can’t disprove a negative” to defend such claims, “you can’t prove Jesus didn’t rise from the dead.” So how is the example about Lions and rising from the dead different? (BTW I am not defending Craig’s statements) ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [November 27, 2014, 3:21pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/2 "2014-11-27T15:21:40Z")
> [@Robert163](#): > > (BTW I am not defending Craig’s statements) Good, because you can’t prove he’s wrong! Personally, I figure almost any proposition can be proven true or proven false, but often not both, and which one depends on how the proposition is phrased. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [November 27, 2014, 3:26pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/3 "2014-11-27T15:26:30Z")
> [@Robert163](#): > > William Lane Craig says you can disprove a negative. For example, “the are no Lions in Africa” can be disproven. Atheists, agnostics and rationalists use the term “you can’t disprove a negative” to defend such claims, “you can’t prove Jesus didn’t rise from the dead.” So how is the example about Lions and rising from the dead different? (BTW I am not defending Craig’s statements) A link to where he says this and why would be nice. I’d like to see his reasoning. ---
**Author:** ![Robert163](https://avatars.discourse-cdn.com/v4/letter/r/4af34b/32.png) [@Robert163](https://boards.straightdope.com/u/Robert163)\ **Post date:** [November 27, 2014, 3:28pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/4 "2014-11-27T15:28:50Z")
> [@Czarcasm](#): > > A link to where he says this and why would be nice. I’d like to see his reasoning. I dont have a link… i saw it in a video a while back ---
**Author:** ![Grumman](https://avatars.discourse-cdn.com/v4/letter/g/43a26b/32.png) [@Grumman](https://boards.straightdope.com/u/Grumman)\ **Post date:** [November 27, 2014, 3:30pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/5 "2014-11-27T15:30:04Z")
The ability to prove a negative depends on how much access you have to the area in which the positive is alleged to have happened. For example, I can prove there isn’t an elephant in my house because I can divide the house into smaller than elephant-sized chunks of space and verify that there is no elephant in any of them. I cannot provide such a strong proof that Jesus did not rise from the dead because all evidence for or against is two thousand years old and on the other side of the planet. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [November 27, 2014, 3:30pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/6 "2014-11-27T15:30:18Z")
> [@Robert163](#): > > William Lane Craig says you can disprove a negative. For example, “the are no Lions in Africa” can be disproven. Atheists, agnostics and rationalists use the term “you can’t disprove a negative” to defend such claims, “you can’t prove Jesus didn’t rise from the dead.” So how is the example about Lions and rising from the dead different? (BTW I am not defending Craig’s statements) We can go to Africa and see whether or not there are lions there (spoiler: there are). We cannot go to where Jesus was buried and see whether or not he rose from the grave. ---
**Author:** ![The\_Other\_Waldo\_Pepper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_other_waldo_pepper/32/12370_2.png) [@The\_Other\_Waldo\_Pepper](https://boards.straightdope.com/u/The_Other_Waldo_Pepper)\ **Post date:** [November 27, 2014, 3:31pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/7 "2014-11-27T15:31:09Z")
> [@Robert163](#): > > William Lane Craig says you can disprove a negative. For example, “the are no Lions in Africa” can be disproven. Atheists, agnostics and rationalists use the term “you can’t disprove a negative” to defend such claims I thought the hard part was _proving_ a negative. If I say there are no lions in Africa, you disprove me by producing one; if you say there are no tuataras in Africa, you prove it by – doing what, exactly? ---
**Author:** ![Robert163](https://avatars.discourse-cdn.com/v4/letter/r/4af34b/32.png) [@Robert163](https://boards.straightdope.com/u/Robert163)\ **Post date:** [November 27, 2014, 3:33pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/8 "2014-11-27T15:33:24Z")
> [@Ethilrist](#): > > We can go to Africa and see whether or not there are lions there (spoiler: there are). > > We cannot go to where Jesus was buried and see whether or not he rose from the grave. > [@The\_Other\_Waldo\_Pepper](#): > > I thought the hard part was _proving_ a negative. > > If I say there are no lions in Africa, you disprove me by producing one; if you say there are no tuataras in Africa, you prove it by – doing what, exactly? ah, ok, thanks ---
**Author:** ![Robert163](https://avatars.discourse-cdn.com/v4/letter/r/4af34b/32.png) [@Robert163](https://boards.straightdope.com/u/Robert163)\ **Post date:** [November 27, 2014, 3:34pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/9 "2014-11-27T15:34:35Z")
> [@Grumman](#): > > The ability to prove a negative depends on how much access you have to the area in which the positive is alleged to have happened. For example, I can prove there isn’t an elephant in my house because I can divide the house into smaller than elephant-sized chunks of space and verify that there is no elephant in any of them. I cannot provide such a strong proof that Jesus did not rise from the dead because all evidence for or against is two thousand years old and on the other side of the planet. ok, thanks ---
**Author:** ![Budget\_Player\_Cadet](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/budget_player_cadet/32/205_2.png) [@Budget\_Player\_Cadet](https://boards.straightdope.com/u/Budget_Player_Cadet)\ **Post date:** [November 27, 2014, 3:35pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/10 "2014-11-27T15:35:31Z")
> [@Robert163](#): > > William Lane Craig says you can disprove a negative. For example, “the are no Lions in Africa” can be disproven. Atheists, agnostics and rationalists use the term “you can’t disprove a negative” to defend such claims, “you can’t prove Jesus didn’t rise from the dead.” So how is the example about Lions and rising from the dead different? (BTW I am not defending Craig’s statements) I was under the impression that the argument was that you couldn’t prove a negative, not that you couldn’t disprove it. It’s trivial to disprove negative statements. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [November 27, 2014, 3:37pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/11 "2014-11-27T15:37:01Z")
> [@The\_Other\_Waldo\_Pepper](#): > > … if you say there are no tuataras in Africa, you prove it by – doing what, exactly? One way would be by examining every object in Africa, and seeing that it is not a tuatara. Another would be by examining every tuatara, and seeing that it is not in Africa. ---
**Author:** ![The\_Other\_Waldo\_Pepper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_other_waldo_pepper/32/12370_2.png) [@The\_Other\_Waldo\_Pepper](https://boards.straightdope.com/u/The_Other_Waldo_Pepper)\ **Post date:** [November 27, 2014, 3:39pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/12 "2014-11-27T15:39:27Z")
That said, you can still prove a negative in various cases. I mean, when I’m hanging out with my family for Thanksgiving this afternoon, I can announce that _"nobody at this table is in their nineties,_ and if pressed could then vindicate myself by going around the room asking each person to give their age – twenty-two, fifty-three, and so on. [Edited to add: dangit, ninja’d!] ---
**Author:** ![Hentor\_the\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/h/8edcca/32.png) [@Hentor\_the\_Barbarian](https://boards.straightdope.com/u/Hentor_the_Barbarian)\ **Post date:** [November 27, 2014, 3:41pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/13 "2014-11-27T15:41:08Z")
> [@Robert163](#): > > ah, ok, thanks See also: > **[Russell's teapot](https://en.m.wikipedia.org/wiki/Russell%27s_teapot)** > > Russell's teapot is an analogy, formulated by the philosopher Bertrand Russell (1872–1970), to illustrate that the philosophic burden of proof lies upon a person making empirically unfalsifiable claims, as opposed to shifting the burden of disproof to others. > Russell specifically applied his analogy in the context of religion. He wrote that if he were to assert, without offering proof, that a teapot, too small to be seen by telescopes, orbits the Sun somewhere in space between the Earth and ... Russell’s Teapot. Prove to me that Russell’s Teapot does not exist. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 27, 2014, 3:45pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/14 "2014-11-27T15:45:12Z")
As an unqualified generalization, the claim that “You can’t disprove a negative,” is simply false. “I don’t exist,” “You don’t exist,” try disproving either of those. I think you will find it is not hard. Generally speaking, all positive assertions can be rephrased (maybe awkwardly) as negatives, and vice versa. “There are faeries at the bottom of my garden” == “The bottom of my garden is not devoid of faeries”. If you can’t disprove a negative, you can’t disprove anything. (And that statement is negative, you can’t disprove it.:p) ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 27, 2014, 3:53pm UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/15 "2014-11-27T15:53:33Z")
> [@Budget\_Player\_Cadet](#): > > I was under the impression that the argument was that you couldn’t prove a negative, not that you couldn’t disprove it. It’s trivial to disprove negative statements. I think you are right, but it is still false. Many negative claims can easily be proved (inasmuch as anything can.) “There are no triangles (in flat, Euclidean space) whose angles add up to more than 180º”. Easy. ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [November 28, 2014, 3:24am UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/16 "2014-11-28T03:24:58Z")
Since it’s Thanksgiving, South Park’s [A History Channel Thanksgiving](http://southpark.wikia.com/wiki/A_History_Channel_Thanksgiving/Script): > [@](#): > > **Narrator** : [more re-enactments] We know the first Thanksgiving was in the fall of 1621, but new evidence suggests that the first exchanging of food between the Pilgrims and Native Americans may have been visited by aliens! [dramatic flashes of darkness as the alien is shown up close, then a picture of a fetus, and then…] > **Duncan Everton** [Professor of History, Oakmont H.S.]: In every journal entry we researched from those early Pilgrims, \*not one entry mentioned anything about aliens not being there. \* [my emphasis] ---
**Author:** ![JWT\_Kottekoe](https://avatars.discourse-cdn.com/v4/letter/j/3ec8ea/32.png) [@JWT\_Kottekoe](https://boards.straightdope.com/u/JWT_Kottekoe)\ **Post date:** [November 28, 2014, 5:42am UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/17 "2014-11-28T05:42:53Z")
I often see the statement “You can’t prove a negative” on the Straight Dope Message Board." This is patently false. Trivial examples abound. Some of the nontrivial examples have been among the most famous proofs in mathematics; for example the ancient proof that there is no rational number that is the square root of two, and the more recent proof that you can’t trisect an angle using straight edge and compass. ---
**Author:** ![Reyemile](https://avatars.discourse-cdn.com/v4/letter/r/46a35a/32.png) [@Reyemile](https://boards.straightdope.com/u/Reyemile)\ **Post date:** [November 28, 2014, 5:43am UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/18 "2014-11-28T05:43:51Z")
> [@Giles](#): > > Another would be by examining every tuatara, and seeing that it is not in Africa. The latter requires you to prove that the set of tuatara’s you examined does compose every tuatara. ---
**Author:** ![Giles](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/giles/32/60_2.png) [@Giles](https://boards.straightdope.com/u/Giles)\ **Post date:** [November 28, 2014, 6:07am UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/19 "2014-11-28T06:07:49Z")
> [@Reyemile](#): > > The latter requires you to prove that the set of tuatara’s you examined does compose every tuatara. Right – that might be hard in some cases, but easy in others. For example, none of my sisters live in Africa (because I have no sisters), and none of my brothers live in Africa (because I have one brother and he lives in Australia). ---
**Author:** ![The\_Other\_Waldo\_Pepper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_other_waldo_pepper/32/12370_2.png) [@The\_Other\_Waldo\_Pepper](https://boards.straightdope.com/u/The_Other_Waldo_Pepper)\ **Post date:** [November 28, 2014, 6:15am UTC](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762/20 "2014-11-28T06:15:32Z")
> [@JWT\_Kottekoe](#): > > I often see the statement “You can’t prove a negative” on the Straight Dope Message Board." This is patently false. Trivial examples abound. Some of the nontrivial examples have been among the most famous proofs in mathematics; for example the ancient proof that there is no rational number that is the square root of two, and the more recent proof that you can’t trisect an angle using straight edge and compass. Not to mention [Fermat’s Last Theorem](http://en.wikipedia.org/wiki/Wiles%27_proof_of_Fermat%27s_Last_Theorem): _“The proof itself is over 150 pages long and consumed seven years of Wiles’ research time.[1] John Coates described the proof as one of the highest achievements of number theory, and John Conway called it the proof of the century.[2] For solving Fermat’s Last Theorem, he was knighted, and received other honours.”_ [Next page](https://boards.straightdope.com/t/william-lane-craig-says-you-can-disprove-a-negative/705762.md?page=2)