10. December 2009 17:08
One is properly guilty of committing the ad hominem fallacy when one tries to refute an argument by going after the character of the proponent of said argument. A refutation based on this approach is invalid – even if the argument turns out to be false. But what about when one distrusts the supporting claims of an argument based on the proponent’s character such that one remains unconvinced? Is one properly guilty in this case of the ad hominem fallacy? Surely not!
During the recent ClimateGate scandal you hear proponents like Dr. Andrew Watson claim their detractors are guilty of character assignation. The implication is obvious and deceiving: opposing skepticism is unreasonable if detractors are going after the character of scientists at the CRI. However, it is perfectly reasonable to consider an individual’s dishonesty when assessing an argument based on their claims. When a climate scientist holds up a chart showing temperatures over time as supporting evidence in their argument for manmade climate change, our trust of those numbers is relevant to said argument.
Courts of law have long held a witness may be impeached resulting in suspect credibility. When the credibility of a witness is suspect, an argument based on their testimony is undermined. In other words, it is acceptable to “go after the person” (ad hominem) to undermine their claims and weaken an argument based on those claims. That is precisely what has happened in the recent ClimateGate affair. The arguments for manmade climate change have not been refuted by this scandal, but they have certainly been undermined by dishonest action.
On the other hand, an area I have witnessed ad hominem proper is in the vilification of the intelligent design community. Here the detractors of ID say their science is bogus because many of the leading proponents are theists. I am guessing these critics would point to bias as a qualifier for impeachment. And if the credibility of some ID proponents is in question, then their science must be as well - so their reasoning goes. However, there is a major difference here when compared to ClimateGate. In the case of climate change we rely on the scientists at research centers like CRI to provide the data (or compiled data) for the formulation of theories. Climate scientists may disagree on which model best fits the data, but if the data is tampered with, the whole enterprise is undermined. In the case of ID, scientists on both sides of the fence are working from a common dataset. If an ID proponent were caught doctoring an electron scan of a bacterial flagellum, then an “IDGate” would be justifiable. But these folks are dismissed a priori because some are theists, not because they have tampered with data. Their dismissal is typically accompanied by claims of refutation, or that ID theories are simply rubbish from the get-go. Not only is this ad hominem, but ironically it cuts both ways. Should we not also dismiss neo-Darwinian theorists on the basis of their philosophical naturalism and atheism?