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It's not a logical standard, and you can prove a negative. For example, I can prove that I'm not dead, that there's no elephant in the room with me as I type t

It's not a logical standard, and you can prove a negative. For example, I can prove that I'm not dead, that there's no elephant in the room with me as I type this, and that my wife is not having sex with someone else right now because I can see her on the couch. I wish people would stop saying you can't prove a negative. You can prove that you didn't do something by proving something else that logically excludes you doing it--such as being somewhere else at the time.

rcstank 5y ago
What about people who can’t prove a negative but truly are innocent? If you can’t guarantee that 100% can prove a negative, then innocent people would be convicted.
- fatbird 5y ago
  Innocent people do get convicted. Some negatives can't be proven, just like some positive assertions can't be proven.
- ganafagol 5y ago
  What about people who can't prove a positive but truly are guilty? In this fuzzy form of what "positive" and "negative" are, there is a symmetry that allows all arguments you have for one "side" to be easily flipped. Each positive is somebody elses negative. Not guilty? Not innocent? With that line of reasong you could not ever prove anything since it's "the negative" of something else. Mathematical logic has a solution to this though. You may want to check out constructive logic. That's where the statement "you can't prove a negative" is reasonable but has very specific meaning.
gassius 5y ago
In Aristotelian Logic, is said that you can't prove an Universal Negative statement. I guess at some point someone forgot the Universal part and ran with it, creating that misconception.
jjk166 5y ago
That's not what I'm talking about. You can't prove an arbitrary negative. Or even more rigorously, just because you can't prove a negative doesn't make the positive true. You could have programmed a script to make this comment. The elephant might be invisible. That might be your wife's identical twin sister. You can always come up with a more elaborate explanation. You haven't proved your negatives, you've just made it harder to prove the inverse. And while specific examples might be easy, in general this is hard if not impossible to do. It would be absurd to assume your wife is cheating at every moment where you can't see with your own eyes that she isn't - no the default assumption must be that the claim is false and evidence must be presented to the contrary.
- fatbird 5y ago
  You're confusing logic with epistemology in the context of legal proceedings and life in general. Epistemically, I prove there's no elephant in my room now because elephants can't be invisible, because I would feel it or hear it or smell it, etc. You can posit an endless number of additional premises to show that there may still be an elephant in the room, but you end up in logical paradox where any evidence of the elephant being present is inaccessible. At that point, what does it mean to say "there's an elephant in here with me that is completely undetectable, so lack of detection is not evidence of absence?" In terms of epistemology, "proof" means reaching sufficient justification for considering a belief to be true, not validity according to an axiomatic system.

rcstank 5y ago

What about people who can’t prove a negative but truly are innocent? If you can’t guarantee that 100% can prove a negative, then innocent people would be convicted.

fatbird 5y ago
Innocent people do get convicted. Some negatives can't be proven, just like some positive assertions can't be proven.
ganafagol 5y ago
What about people who can't prove a positive but truly are guilty? In this fuzzy form of what "positive" and "negative" are, there is a symmetry that allows all arguments you have for one "side" to be easily flipped. Each positive is somebody elses negative. Not guilty? Not innocent? With that line of reasong you could not ever prove anything since it's "the negative" of something else. Mathematical logic has a solution to this though. You may want to check out constructive logic. That's where the statement "you can't prove a negative" is reasonable but has very specific meaning.

gassius 5y ago

In Aristotelian Logic, is said that you can't prove an Universal Negative statement. I guess at some point someone forgot the Universal part and ran with it, creating that misconception.

jjk166 5y ago

That's not what I'm talking about. You can't prove an arbitrary negative. Or even more rigorously, just because you can't prove a negative doesn't make the positive true. You could have programmed a script to make this comment. The elephant might be invisible. That might be your wife's identical twin sister. You can always come up with a more elaborate explanation. You haven't proved your negatives, you've just made it harder to prove the inverse. And while specific examples might be easy, in general this is hard if not impossible to do. It would be absurd to assume your wife is cheating at every moment where you can't see with your own eyes that she isn't - no the default assumption must be that the claim is false and evidence must be presented to the contrary.

fatbird 5y ago
You're confusing logic with epistemology in the context of legal proceedings and life in general. Epistemically, I prove there's no elephant in my room now because elephants can't be invisible, because I would feel it or hear it or smell it, etc. You can posit an endless number of additional premises to show that there may still be an elephant in the room, but you end up in logical paradox where any evidence of the elephant being present is inaccessible. At that point, what does it mean to say "there's an elephant in here with me that is completely undetectable, so lack of detection is not evidence of absence?" In terms of epistemology, "proof" means reaching sufficient justification for considering a belief to be true, not validity according to an axiomatic system.