Is it possible to prove a negative?

[YeshuaRedeemed]

I can prove that the jelly beans are not in the jar by turning the jar upside down. When nothing falls out, I have proven a negative. What are your thoughts?

 

[Revoltingest]

You've proven a negative.
Another old saw bites the dust.

 

[YeshuaRedeemed]

You've proven a negative.
Another old saw bites the dust.

LOL!

 

[Unveiled Artist]

I can prove that the jelly beans are not in the jar by turning the jar upside down. When nothing falls out, I have proven a negative. What are your thoughts?

You made an empty claim. We can see nothing is in the jar, so when you turn it upside down, we are not surprised. You didnt prove nothing was there; because, there wasnt anything there to begin with.

Since nothing was there, basically, you are making a meaningless claim. Kind of life using an imaginary knife to cut an imaginary sandwhich and when the sandwhich doesnt cut, you say its proof even though there was nothing there to begin with.

Basically, you cant prove a negative. Reminds me of a magician saying; see, there is nothing in my hand. Now if I close my hand and turn it over, and say POOF, and open my hands again, see! nothing is there.

There is a term for it. Cant think of it at the moment.

 

[David T]

You made an empty claim. We can see nothing is in the jar, so when you turn it upside down, we are not surprised. You didnt prove nothing was there; because, there wasnt anything there to begin with.

Since nothing was there, basically, you are making a meaningless claim. Kind of life using an imaginary knife to cut an imaginary sandwhich and when the sandwhich doesnt cut, you say its proof even though there was nothing there to begin with.

Basically, you cant prove a negative. Reminds me of a magician saying; see, there is nothing in my hand. Now if I close my hand and turn it over, and say POOF, and open my hands again, see! nothing is there.

There is a term for it. Cant think of it at the moment.

"There is a term for it. Cant think of it at the moment".
Normal.

 

[Sunstone]

In folk logic, you cannot prove a negative.

In real logic, you can not only prove a negative, but it's actually easy to do. There are no professional logicians who think it's impossible to prove a negative.

In the first place, any positive proposition can be restated as a negative proposition thanks to the rule of double negation. The rule states that p is logically equivalent to not not p. "The dog barked" is logically equivalent to "The dog did not not bark". P is true is logically equivalent to p is not false.

Again, one of the laws of logic -- the law of non-contradiction -- is a negative. It states that a proposition cannot be both true and not true. Or, put differently, a proposition cannot be both true and false. The law can be derived formally -- that is proven with deductive certainty.

But what about such things as the Loch Ness Monster, Big Foot, or God? That is, can you prove that something does not exist? The question turns on what you mean by "prove"? For instance, you cannot prove with absolute certainty that a pink elephant does not exist using inductive logic. But you cannot prove with absolute certainty anything using inductive logic. You can't even prove that tomorrow the sun will rise. Induction does not deal with certainty, but with probability.

So the issue is, what level of probability do you need that something does not exist before you consider it "proved" that something does not exist? If you demand absolute proof, then are you willing to apply the same high standard of requiring absolute proof to everything? What about to whether or not the water you will drink today is poisoned and that you will die if you drink it? If you need absolute proof pink elephants don't exist in order to behave as if they don't exist, do you need absolute proof your water won't kill you in order to drink it?

If you're going to dismiss inductive arguments because they do not provide absolute certainty of the nonexistence of things, are you going to be consistent and always dismiss them -- or just dismiss them when you have whim to dismiss them?

 

[Stevicus]

Pink elephants exist.

 

[Axe Elf]

What @Sunstone said, and I'll add that the concept of being unable to prove a negative comes from taking a precept of the scientific method out of context.

Suppose you are testing for the effects of telepathy, for instance. You have what is called a "null hypothesis," which is the hypothesis that what you are testing for does not exist, and then you have an "alternative hypothesis," which is the hypothesis that what you are testing for does exist. If you observe the results of several trials and find that the "hits" are not statistically significant (that is, that the number of hits is not significantly greater than what you would expect by chance less than 5% of the time), then you cannot accept the alternative hypothesis--that you have successfully measured the effects of an existing effect, namely telepathy.

BUT--you also cannot accept the null hypothesis. You cannot accept that you have demonstrated conclusively that telepathy does not exist--just that you have not successfully measured it in this experiment. So researchers never say that they accepted the null hypothesis; they can only say that they failed to reject the null hypothesis.

In other words, you can't scientifically prove a negative (a null hypothesis). But it's not a universally ironclad law that applies to all situations outside of science. I can prove that I am not in Nebraska, for instance.

 

[lewisnotmiller]

I can prove that I am not in Nebraska, for instance.

Is that by taking a photo in which you're not holding corn???

In any case, liked your post, and @Sunstone s

 

[Twilight Hue]

I can prove that the jelly beans are not in the jar by turning the jar upside down. When nothing falls out, I have proven a negative. What are your thoughts?

How long was the jar left out in the sun?