Argumentum ad hominem
This is a fallacy we studied before but it bears repeating, not least because it's perhaps the most frequently charged and least understood, in spite of its relative simplicity. Consider the following example:
You say that the conservatives' tax plans would leave the health service under-funded, but you're a liberal and would get rid of health care altogether.
Now, whether or not the characterization of the so-called liberal's beliefs is accurate (that question will be asked when we look at another fallacy to come), the point is that it
isn't relevant: either the plans really will leave the health service under-funded or they won't (or, perhaps, the situation may be considerably more complex), but the political persuasion of the person making that criticism doesn't impact on the claim itself. That means that the complaint against the liberal is against him or her,
not the claim; and that is what the Latin phrase means: an
argument against the man (or woman—more accurately, "argument to the person"), rather than an actual counter-argument. In general, there are three kinds of ad hominem:
- Abusive—the person is attacked instead of their argument
- Circumstantial—the person's circumstances in making the argument are discussed instead of the argument itself
- Tu Quoque—the person is said to not practice what he or she preaches
Notice what the ad hominem is
not: it doesn't say that the political beliefs of the liberal don't motivate his or her criticism in the first place, or that he or she wouldn't want to remove health care altogether (although it doesn't seem likely), but only that these things are not
relevant to the point at issue. For this reason it is usually grouped as one of the fallacies of relevance. It also is not equivalent to an insult, as many people seem to suppose.
Consider now some other examples:
Some politicians claim we should raise taxes, but they are just greedy opportunists trying to gain more of our money to spend on themselves.
This is an ad hominem abusive, since it attacks a (perceived) quality of the claimant(s) instead of the claim itself. It has the form:
P1: A claims B;
P2: A is a C;
C: Therefore, B is false.
You say we should lower taxes, but you are living beyond your means and so you would be expected to say that.
