3 ms·
Strictly speaking, you're proving the positive assertion that you were born after the assassination, which is incompatible with your having been the assassin. Y
by rosser 15y ago
Strictly speaking, you're proving the positive assertion that you were born after the assassination, which is incompatible with your having been the assassin. You can only prove or disprove a positive assertion. "Proving a negative" is done by proving a positive assertion that's contrary to, or incompatible with the thing you're trying to "disprove".
- vecter 15y agoIf proving the positive assertion implies the negative assertion, what's the difference?
- anigbrowl 15y agoI do not believe in the existence of fire-breathing dragons outside of fiction, but I can't prove they don't exist. See also: UFOs, angels, god(s), and so on. In logic, the onus is on the person making the positive claim (that such things do exist) to furnish the evidence to back it up. The skeptic's lack of knowledge is not proof of non-existence, of course.
- vecter 15y agoI'm talking about mathematical truths for which establishing non-existence follows directly from proving a positive assertion, not that white ravens don't exist.
- anigbrowl 15y agoI understand that, but 'proving a negative' is philosophical shorthand for the latter rather than the former. You are just going to have to put up with the slight vagueness of the term.