Let's put this common refrain to rest~ something that I hear all the time in arguments concerning religion.  It goes something like this:

" Remember, you can't prove a negative!"

Really people?

This has become much more common, especially in the arguments amongst Atheists and agnostics concerning certainty, and it really puzzles me how people can be skeptical and free-thinkers, yet take to an idea so easily and not question it.  I will elaborate on this a little more once I have the time, but let me start all of those "can't prove a negative" types off with a question~ " I am not sitting at my desk."  Thats a negative claim.  Are you telling me that there is no way to confirm or disprove that?

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Cane, you are clearly using definition 1c of dogma: a point of view or tenet put forth as authoritative without adequate grounds. I am definitely using that definition. And you clearly have a very low opinion of logic, without which we know nothing whatsoever apart from our most primitive sensations.
My opinion of logic is irrelevant. You have told me what I am doing, not what you think knowledge is. Tell me, what does it mean to know.
Cane, your opinion of logic is central to your inability to admit that impossible things are impossible, except for your logically impossible negative claim that negative claims are impossible to prove. That you think logic and dogma are somehow linked, when in fact they are essentially polar opposites says that you are not particularly interested in knowledge. It is bizarre that you persist. At this point, I'm writing you off as a troll.
Thanks! Enjoy your superior status and your comfort at being right. You cannot prove a negative, unless you want to prove it beyond a shadow of a doubt. But then you get into the realm of law, not science.

Cane, our relative levels of intellect have nothing to do with it. My feelings have nothing to do with it. It is this simple:


"You cannot prove a negative" is a self-negating proposition. You either can't or won't see this.


If you can't, then perhaps we have some evidence of an intellect differential. If you won't, then you are simply trolling and wasting everybody's time to get your jollies. Either way, since your fundamental axiom is incorrect and you are unwilling to abandon it despite repeated demonstrations of its obvious falseness, we have no basis for discussion. Enjoy your little mind games.

Jason, that kind of aggression really wasn't called-for at all. The epistemology of knowledge is a long-standing, worthwhile topic and the responses weren't going in circles yet - until you jumped on calling "troll".


I'm sure that's the tone you use for arguing "fundamentalists" out of their religions (with no success whatsoever, just spite), but it puts someone on the defensive almost instantly when you attempt to damage or manipulate their personal identity. 


Cane's position did relate very well to one of the most common logical issues: the presumption that "possible" is sufficient for "necessary". I would surmise that his response was to reject the entire class of a priori knowledge in favor of a posteriori affirmative statements. That is actually a reasonable approach because it inherently excludes self-contradictory statements (since they can't be found a posteriori).


His primary mistake was in being a bit hasty in his rejection of a priori knowledge because he lost access to logical transformations of a posteriori knowledge-- such as providing exclusionary proof for negative statements. While I believe he would do better with a more expansive epistemological approach, I had no problem arguing for additional aspects to expand his current framework.


That's how philosophy works; you have to find an anchor point and build your framework outward from there, often over the period of years or decades. So if his approach missed something critical, then we should argue for an expansion of his ideas, not for the subversion or deconstruction of his investment unless it contains explicit contradictions.


As far as I see, Cane's ideas held no contradictions; they simply strike me as being incomplete and improvable. He was very careful to qualify his skepticism about proof for negative statements as a belief, not a proven negative statement, so the entire basis of your attacks against him seem baseless (and really, quite sloppy for the oversight). 


It could be worthwhile to have an extended discussion about the nature of persuasion and how to approach the modification of other's personal identities, but probably in a separate thread.

"That is actually a reasonable approach because it inherently excludes self-contradictory statements (since they can't be found a posteriori)."

-What? Rejecting the entire class of said a priori knowledge is what creates the contradiction that one can be certain that certainty is impossible.

I think it is contradictory to hold that one cannot be certain and it is not to hold that one can have knowledge that since a thing is not possible, it cannot exist. A system that hold causality and non-contradiction as universal has the least contradictions, imo.

The rejection of a priori knowledge has historical precedent, so it's not an unreasonable stance to take, even though I consider it to be less effective than a broader view.


If I were to restate Cane's position, I would say that he is "certain in the belief that no means for proving a negative statement will be found by evidentiary means." He made a non-evidentiary prediction, not a binding conclusion, and that's valid to extent that his approach allows exclusions.

Drake, have you been following the "100% Positive" thread? http://www.atheistnexus.org/forum/topics/is-everybody-100-positive


Cane has been posting there relentlessly, refusing to acknowledge the simplest points, but rather persisting in pushing bizarre and idiosyncratic definitions, despite repeated demonstrations of his simple logical errors. He may not actually be a troll, but it is not too soon to suspect him of it.


You say, "if his approach missed something critical, then we should argue for an expansion of his ideas". We did that, repeatedly and extensively. I apologize for not being infinitely patient, but I am not an infinite being.

In science, you can be wrong or right. In logic, your idea can be possible, existent, or impossible. Logic is whether it is possible for something to exist in the real world. Science answers if something is in the real world. They are incompatible and that is why we disagree. With science, you cannot prove a negative. And apparently, in logic, it does not make sense to say you cannot prove a negative. Or at least, "You cannot prove a negative" is a self-negating proposition (whatever that means).

Cane, if you truly believe that science and logic are incompatible, then you understand neither. Again, your bizarre definition of logic is confusing you. It's impossible to do science without logic. Logic is a fundamental underpinning of the scientific enterprise. If this were not true, then scientific conclusions could not exist. Logic is how you get from hypothesis to evidence to conclusion.


And by self-negating proposition, I mean simply that if the proposition is true, it must be false. Which is definitely the case with "you cannot prove a negative". This statement is itself a negative. For it to be true, it would have to be false. This is not the kind of thing you want to base your reasoning on.

Hi Jason,


I actually find that to be a fairly cheap evasion. First of all, I think you're blurring the line between something being true and something being proven true. For instance, the statement "you cannot prove a negative" may well be true. This does not create a logical contradiction unless you actually claim that you can prove the statement "you cannot prove a negative".

This is analogous to our inability to prove certain mathematical theorems, despite them being almost certainly true. The inability to prove something is distinct from whether or not it is actually true. And the same goes for many subjective facts about us.


Besides, the whole business of self-negating statements gets fuzzy anyway.

One of the ones I often hear is the comeback to "Absolute knowledge does not exist.", which is "Is that an absolute claim?". But it's cheap: that statement may well be absolutely true, despite our logical inability to hold it as an absolute.


I find "You cannot prove a negative." to be a perfectly intelligible statement.


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