Fallacy Fallacy

Also called

 * Appeal to Fallacy
 * Mister Spock Fallacy
 * Wrong Means Fallacy

Claiming that a position must be false because the argument used to get to that position used a fallacy. It may sound like a rational thing to do since by definition a fallacious argument makes no sense, and this rule may seem like a frustrating Mind Screw to understand, but...

""Take the fraction 16/64. Now, canceling a six on top and a six on the bottom, we get that 16/64 = 1/4."

"That's rubbish. Taking digits away is not a valid way to simplify a fraction. Therefore, 16/64 is not equal to 1/4.""


 * Another excellent proof of how a false argument can result in a true conclusion: in medicine, pressure around the brain can cause severe headaches. Ancient surgeons assumed that it must be demons in the patient's head causing the pain, and that exposing them to light would kill them or drive them out; therefore, they drilled holes in the patient's skull. The end result relieved the pressure and actually did cure the headaches, even though their reasoning was entirely faulty.


 * Likewise the use of red lighting to treat smallpox. (By placing dyed cloth over the windows of a room.) This was believed to aid the balance of humours in the body. Now it is assumed to have been effective because the red dye was a natural shield against ultraviolet light.
 * Any Straw Vulcan character is bound to be written as if "illogical" is a synonym for "wrong."
 * A good many theories about the world over the years including many scientific ones have taken observations and filled in the gaps with guesses that lead to the right conclusions but for the wrong reasons. Freud's theories, for example, are sometimes useful but are based on dated inaccurate knowledge of the mind.
 * Young Earth creationists employ this regularly to attack evolution theory on the basis that early evolutionary models have had to be discredited and revised and that some early evidence of transitional forms (such as the Piltdown Man) turned out to be frauds. Of course, in some cases, they're simply trying to argue that this proves that certain advocates are more committed to the idea than the facts.
 * A joke: Three old men went to the doctor for their checkup. Since they're getting on in years the doctor decides he should check their mental faculties as well. So he asks the first man, "What's three times three?" "273." Then he asks the second man the same question. "Tuesday." Finally he asks the third man. "9." "Great! How did you get that answer?" "I subtracted 273 from Tuesday."
 * Of course, a proposition may fallaciously be declared correct due to an argument against it fallaciously declaring it incorrect due to a particular argument for it being fallacious, thus committing the Fallacy Fallacy Fallacy.
 * One specific Fallacy Fallacy is based off of the Appeal to Ridicule. This is very common in political debates, wherein if an individual ridicules some position without backing up the ridicule, the opposing side will assume that the Appeal to Ridicule was made because the person has no actual argument to make. Instead, the person who made the argument was just trying to be funny, or was just taking some time to enjoy disparaging the opposition. And of course, even if the person was engaging in a fallacy, it doesn't say anything about others who share their point, and may very well be able to back up their claims.
 * There's even a proverb pointing out this problem: "a broken clock is still right twice a day".