En garde!
Do you admire them for their willingness to defend themselves?
Admire, not really. But I appreciate someone who can reason their position well.
If they didn’t defend themselves, would you see that as a sign of weakness?
No, if I question your position, whether you defend it or not is only that.
Do you see the defensiveness, itself, as a sign of weakness.
Defensiveness as in “I’m right, that’s all I have to say; nothing you say will make me change my mind; it doesn’t matter what you think it’s about what I know.” yeah, that’s weak. But in the sense of sticking to their position until the last tent pole falls, I’ve got no issue with that.
Would they be so defensive if they didn’t think they were so weak?
Not sure I’d agree with that, defensiveness can be a natural reaction to being challenged especially if they don’t know why or are wary of the others motives; but the “I’m right because I say so” argument or refusing to hear or consider questioning does make me wonder about what’s up.
Suppose the defense consisted of ad hominem attacks or appeals to authority—would that seem persuasive to you?
Ad hominem attacks annoy me. Appeals to authority are fine if properly based (i.e. the authority is actually an authority and their reasoning isn’t isolated) but, if I have enough knowledge on the subject I won’t accept it carte blanche.
Suppose the ad hominem attacks were a response to an initial ad hominem attack? Would that make it more legitimate?
Nope, just more annoying.
If you are attacked, do you think it’s better to hold fire or to go instantly on the counter-attack?
Depends on my mood, if I’m up for a good debate, I’m all in guns blazing. If it’s just baiting or I’m distracted I might see where they want to go with it. Otherwise, life is busy, I can’t stop every time someone disagrees with me or I with them.
When deciding this, do you consider what non-combatants will think of your strategy, or is that irrelevant?
You’re in or your out. If you want to sit on the sidelines and get huffy about it, that’s your business, if you have something to say speak up – that’s what debates are for (in my opinion).