I think we should be more careful about separating heuristics and biases. Heuristics are biased compared to perfect thought, but that’s a pointless comparison. You can accuse someone of overusing a heuristic beyond optimal use, but that’s a lot weaker than saying it would be better not to use it. Calling things fallacies implies that they’re not worth using at all, which is often wrong. Arguments never take the simple deductive form you portray. Ad hominem is a legitimate heuristic and calling it a fallacy is a mistake. But everyone does it, so “fallacy” is a pretty weak word.
I don’t see much difference between (A) and (C). Translation between formal and informal usually is contentious.
Ad hominems are not always fallacious, but the ad hominem fallacy is. The character, circumstances, or actions of the arguer have no bearing on whether the argument’s conclusion follows from its premises.
The character of the speaker could be a good reason to question the truth-value of the speaker’s claims. And given limited time/resources, it might be a good enough reason to not bother to listen to the speaker’s argument. But it is never what makes an argument invalid, regardless of whether one is reasoning deductively. If you disagree, please give a counterexample.
ETA: it’s also never what makes it the case that p is false, unless the speaker’s character is directly linked to the proposition somehow. (like in the proposition, “I am a good person”)
I think we should be more careful about separating heuristics and biases. Heuristics are biased compared to perfect thought, but that’s a pointless comparison. You can accuse someone of overusing a heuristic beyond optimal use, but that’s a lot weaker than saying it would be better not to use it. Calling things fallacies implies that they’re not worth using at all, which is often wrong. Arguments never take the simple deductive form you portray. Ad hominem is a legitimate heuristic and calling it a fallacy is a mistake. But everyone does it, so “fallacy” is a pretty weak word.
I don’t see much difference between (A) and (C). Translation between formal and informal usually is contentious.
Ad hominems are not always fallacious, but the ad hominem fallacy is. The character, circumstances, or actions of the arguer have no bearing on whether the argument’s conclusion follows from its premises.
The character of the speaker could be a good reason to question the truth-value of the speaker’s claims. And given limited time/resources, it might be a good enough reason to not bother to listen to the speaker’s argument. But it is never what makes an argument invalid, regardless of whether one is reasoning deductively. If you disagree, please give a counterexample.
ETA: it’s also never what makes it the case that p is false, unless the speaker’s character is directly linked to the proposition somehow. (like in the proposition, “I am a good person”)