I measure this in terms of a personal judgement that an objective or hostile third party would declare that my opponent has failed, which is not the same as “winning.” It’s impossible for me to win an argument, only to lose it. “Winning” would imply that there’s no additional argument which could not be constructed to defeat my current argument. I can’t prove the nonexistence of such an argument.
(I argue against the ideal, not the opponent; my opponent can lose, but my argument cannot win.)
I measure this in terms of a personal judgement that an objective or hostile third party would declare that my opponent has failed, which is not the same as “winning.” It’s impossible for me to win an argument, only to lose it. “Winning” would imply that there’s no additional argument which could not be constructed to defeat my current argument. I can’t prove the nonexistence of such an argument.
(I argue against the ideal, not the opponent; my opponent can lose, but my argument cannot win.)