This has been bugging me for awhile now, so let's get this straight people. If you're gonna throw out the Ad Hominem card, please know what it means.
The various types of argumentum ad hominem are logical fallacies used to counter an argument of an opponent solely by changing the topic to a personal attack on that opponent.
Simply attacking someone or pointing out that they are contemptible is NOT an ad hominem fallacy. One must be using such an attack to avoid factually countering a given claim.
Many of you will notice that the people who shout this out the loudest and most often are people who say things like "you are ignorant of this topic" or "obviously you don't know what you are talking about" instead of directly rebutting the pointed arguments of their marks, excuse me, fellow fraysters.
Classically, these are in fact argumentum ad personam attacks, which have nothing to do with the validity of the point being made. It is a logical fallacy to believe that because someone is commenting on something outside of their field of expertise, such comments will automatically be wrong. Ironically, a number of our "race realist" friends have accused others of ad hominem attacks in the very same phrase as they themselves are engaging in one. This is not surprising, as the "race realist" websites conduct crash courses to teach their recruits how to argue this issue.
Why, you may ask, is it then not ad hominem for myself and others to point out the racist ties of Rushton, Lynn, Taylor, Sailer and their brethren? Depending on how it is phrased, it could, in fact, fall into the category of ad hominem circumstantiae as it questions the bias of the people making an argument without dealing with the argument directly. This can also be a "guilt by association" argument as well. The deciding factor is what the poster is trying to say with such an attack. If we were to say that these people are racists, and therefore, solely on this basis, their arguments are automatically worthless, we would be making an ad hominem attack.
However, to introduce bias, untrustworthiness, or motive for disingenuous behavior into an argument that also directly challenges the factual assertions of say Saletan or Rushton, is not only not ad hominem, but is standard practice in logic, debate, and legal proceedings worldwide.
The theory of evidence depends to a large degree on assessments of the credibility of witnesses, including eyewitness evidence and expert witness
evidence. Evidence that a purported eyewitness is unreliable, or has a
motive for lying, or that a purported expert witness lacks the claimed
expertise can play a major role in making judgements from evidence.
Thus, to point out the fact that Rushton heads the Pioneer Fund (an organization created to promote white supremacy), has appeared at racist conventions alongside David Duke, Don Black and other klansmen, and has longstanding personal friendships with neo-nazis... within the context of a multifaceted debate on his methodology and untrustworthiness as an expert on anything remotely genetic... while being an attack, is simply not an ad hominem logical fallacy. (despite what David Duke, Don Black, & Steve Sailer might instruct on their websites)
Let me repeat. Impugning the character or reliability of a source is not an ad hominem fallacy unless the entire argument against a point hinges on this character attack.
While I am happy that many small-minded individuals have recently upgraded their vocabularies to include "straw man," "ad hominem," and "poisoning the well," they could at least study the concepts of their red herring fallacies before passing them out like free business cards. (not an insult to disprove their conjectures, thus, not ad hominem)
Interestingly enough, if one of us makes an argument that so & so is a racist, the opposition's merely calling out ad hominem is itself an ad hominem fallacy if they make no effort to disprove the allegations of racism. (which no one has even attempted BTW)
Logical fallacies are very interesting, and we see many of them from our trollish comrades. Arguments to authority from people claiming to be experts. The old argumentum ad nauseam... if you repeat it enough it must be true. The existential fallacy, appeals to probability, fallacy of neccesity, Ipsedixitism & honor by association... I could go on.
Point is. Rushton's being a rabid racist is, in fact, a valid critique of his reliability as an expert in racial differences. Couple this with frequently cited, but never directly addressed arguments like eminent biologist Joseph L. Graves' in his 2004 book The Race Myth <link> which call into question the very notion of a biologically reality to the fundamental term in Saletan's hypothesis (race), or the literally dozens of other links to mainstream geneticists, neurologists and other experts who deny everything from the notion of 'g' to the "culturally fair" nature of IQ testing... and you have the makings of a very real case. Instead of crying ad hominem, you need to be trying to prove how these scientists are wrong. Coming up with at least one actual ethical use to which this "research" could be put to would be nice as well.
Oh... and simply shouting over & over that Gould was a Marxist is ad hominem, because the Mis-measure of Man did not serve to justify any Marxist beliefs. Nor does it make any challenge to his assertions. And, perhaps, most importantly no one on those threads was even quoting him.