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. ...
Tu Quoque—the person is said to not practice what he or she preaches ...
You say people should learn to live within their means, but you are in debt yourself and make no effort to get out of it.
This is an ad hominem tu quoque, since it draws to our attention an
inconsistency in the argument: if the claim is true, then the claimant should either change his or her ways or admit that the claim doesn't have to apply to everyone after all. It has the form:
P1: A claims B;
P2: A practices not-B;
C: Therefore, B is inconsistent with A's actions.
...
Pointing out an inconsistency in someone's thinking does not show their
position to be mistaken but it may show their
advocacy of it to be hypocritical. If we change the form slightly, it becomes fallacious:
P1: A claims B;
P2: A practices not-B;
C: Therefore, B is false.
That someone may be a hypocrite, of course, does not show their ideas to be false. The first form of
tu quoque is fine but the latter is fallacious. In summary, then, the ad hominem fallacy brings irrelevancies to a discussion and distracts from the real point at issue.
