Wikipedia has so many discussions among its editing community, with so many bad rhetorical strategies repeating themselves, that it has developed a number of pages on "arguments to avoid" in discussions. For instance, for deletion discussions, the participant is advised on such esoterical problems as "notability fallacies" and "meta-reasoning."
In Internet discussions relating to more philosophical matters, particularly religion and science (both of them subjects of this blog), there are a lot of tired and false arguments that seduce intelligent people. Here are a few:
Argument by sneer.Discussions of religion touch very deep in the people's hearts and psyches, and it can be easy to fall into the trap of seeing one's perceived opponents, or their positions, as stupid, wrong, ridiculous. Thus is born the argument by sneer. Its hallmarks are sarcasm and a patronizing tone.
The fallacy: Insulting a position does not make it false.
The ad hominem attack.In an ad hominem attack, the argument is directed against the character of a person holding a position, rather than against the position. In a milder version, it may be a form of the association fallacy: Would you want to share an opinion with so-and-so despicable person? A more virulent version is an assertion of "poisoned thinking": So-and-so is so despicable that everything he thinks of is tainted!
The fallacy: An argument is not falsified when it is promoted by an undesirable person.
The extrapolated ad hominem attack.The expanded version of the ad hominem attack may apply to an entire organization. In the wake of the sex-abuse scandals, it was frequently applied to the Catholic Church; many people rejected its teachings and philosophies because of bad actors within the Church.
The fallacy: The value of an group's ideals is not nullified by those who do not act by those ideals.
Corrollary: Don't judge a book by its hypocrites.
The reductio ad Hitlerum.This is a special case of the association fallacy. It goes as follows: "Hitler supported X, therefore X is evil." Its inverse is "Hitler opposed X, therefore X is good." A cynical way to refute the association fallacy is to observe, "Even a blind squirrel finds a nut once in a while."
The fallacy: The value of an argument is not affected by the moral character of a person who espouses it.
The unintentional straw man.A proponent of an argument may, due to ignorance, misrepresent the argument. Her opponent falsifies the misrepresentation, and on that basis declares the original argument false. Unlike the classic "straw man" attack, no mendacity is involved. The solution is to do your research when arguing against a position.
The fallacy: If Y is not equal to X, falsifying Y does not refute X.