Argumentum ad hominem was Re: Michael Crichton dies

[David Marjanovic <david.marjanovic@gmx.at>]

> No.  ad hominem doesn't jsut mean saying anything unpleasant about
> somebody.  It means dismissing an argument, without engaging it, on
> the basis of who made it.  For example, if someone denied the validity
> of the taxon Xenoposeidon by saying "Oh, that Taylor is obsessed by
> sauropod vertebrae", then _that_ would be an ad-hominen argument.

This works the other way around, too: if I say "*Xenoposeidon* just _has_ to 
be valid because that Taylor is an expert on sauropod vertebrae", that, too, 
is an ad hominem argument, because there, too, I'm evaluating the person who 
came up with an idea rather than the idea itself.