Grammar, Usage /
Logical Fallacies (for debate and persuasive writing) [23]
Hmmm . . . Tyler, you have used the word "appose" when you meant to say "oppose." Clearly nothing you have to say on the issue of logical fallacies is correct.
Sorry, I couldn't resist :-)
This is an excellent thread, and you are to be commended for starting it. Your list of fallacies and your explanations of them are wonderful in every way, apart from your misuse of "appose."
Other fallacies:
The argument from authority: This occurs when the person arguing attempts to substitutes names of prominent supporters of a position in place of actual arguments. An example taken from another thread:
Nick94: "Scientists like Dr. Lee Spetner and Dr. Werner Gitt agree that mutation has never added information to the genetic code."
Look at those big "Dr."s! And in case you missed it, they're
scientists! Of course, that these two people have degrees and agree on the truth of a statement does not make that statement actually true. In this case, it's doubly misleading, as there are far more "Dr."s out there, over 90% of scientists in biology, who disagree with them. More to the point, even if they had numbers on their side, the truth of an argument does not hinge upon popular support for it. At best, pointing out that over 90% of scientists believe that mutation can add to the genetic code is only a good reason for suggesting that someone go out and read the arguments those scientists have made. It should not be a substitute for those arguments, or used to refute objections to them.
Post Hoc, Ergo Propter Hoc (After this, therefore because of this): This argument mistakes correlation for causation. Causation is very, very difficult to prove, and correlation is very, very easy to notice, so this error comes up a lot.
Example: After guns were banned in 1990, violent crime dropped 5% from 1991-1995. Clearly, banning guns lowers crime rates.
Not really. The crime rate may have been going down for years before guns were banned, in which case the trend would merely have continued unchanged. If the crime rate had been dropping at a rate of 2% a year from 1985-1990, the statistics could even be taken as evidence that banning guns increases crime rates, though that would probably be to make a similar mistake in the other direction. More likely, there are a host of other factors that would have to be controlled for before one could make any assertion about the effects of gun control on crime.
The slippery slope argument: Also very common, this one is often used, quite sincerely and earnestly, by people who should know better. It consists of saying, essentially, that while X might be all right on its own, it might lead to Y, which would be unacceptable.
Example: Euthanasia for the terminally ill who request it may not seem so bad, but allowing this practice would eventually lead to families killing off elderly relatives whose health care costs are too high with the blessings of the medical establishment.
Letting people get away with murder under the pretense of carrying out euthanasia would be bad. This in no way addresses the question of whether genuinely euthanizing the terminally ill is good. In essence, it is a form of straw man argument, in that the arguer is substituting Y, which is much easier to argue against, for X, the thing that is actually being debated.
Well, this post is getting a tad long, so I'll leave it there for now. As to Eric's question, what you are describing isn't a fallacy so much as a lie. Such claims often rely on people's scientific ignorance combined with an argument from authority (DNA proves it, and everyone knows that DNA evidence is irrefutable). Statistics are often abused in this way, because so many people nowadays are largely innumerate. To educate yourself against this sort of statistical abuse, I recommend reading any or all of the works of John Allen Paulos.