What is ad hominem

[swansont]

This is a subject that comes up from time to time in reported posts, but is rarely on target; it's usually just a complaint that someone said something snarky.

There was a thread on this some years ago, but as that got bogged down with some particular instances, I thought just a general discussion might suffice

I've imported a few statements from the other thread that are useful

On 6/29/2012 at 11:54 AM, imatfaal said:

The ad hominem logical fallacy is not merely (or necessarily) an insult - it is a specious form of argument that characterises the opponent and then uses this characterisation to cast doubt upon the opponents argument.

On 6/29/2012 at 3:58 PM, swansont said:

an insult is not necessarily an ad hominem; an insult becomes the fallacy only when it's used as part of an argument or as an excuse to not make a response to an argument.

 

On 6/29/2012 at 4:34 PM, Cap'n Refsmmat said:

"You're stupid" is not an ad hominem argument. "You're stupid, so your argument is obviously wrong" is clearly an ad hominem, because it uses insult rather than logic to attack an argument.

 

I'll add to this that an ad hominem need not include an insult, but merely a personal observation. "You are wrong because bald/old/tall people are never right" is an ad hominem because a personal observation is used instead of refuting some actual point.