Today we'll start covering fallacies in brief. I think we've covered all the crucial ones at this point, but fallacies tend to come and go over time, and so even those which aren't often used now may come back in a decade or two. (Beside, the fallacies I see in use may not be the same fallacies that you see in use.)
And so I'll give brief coverage to a larger number of additional fallacies. Here we go:
The appeal to probability: A statement that takes something for granted because it would probably, or might, be true. For example:
Sixty percent of all such computer problems are viruses; that's what this has to be.
It doesn't have to be that, of course.
Argument from fallacy: The assumption that because an argument for some conclusion is fallacious, then the conclusion must be false. This is bad thinking, of course, because a bad argument can sometimes produce a correct conclusion by accident. As the old saying goes, "Even a stopped clock is right twice a day."
Continuum fallacy: Rejecting a claim because it is imprecise. A claim, of course, is not wrong because it is stated badly; something is wrong because it fails to match reality.
Someone failing to state a claim perfectly isn't a valid reason to dismiss it. More likely, the person dismissing the claim is trying to get an easy win, and is intimidating the person making the claim and hoping to chase them away.
An honest man or women will say something like, "I don't think you're making your case very well, Bob. Let me try to restate it for you, then you tell me if I'm missing something." After that, a precise analysis can be made and the truth of the matter will (hopefully) be discovered.
Many true statements have been badly made, but that didn't make them less true; it merely made them hard to communicate.
Suppressed correlative: This is an argument that ignores or redefines the initial statement to make an alternative impossible. For example:
You're putting on weight, Bob.
No I'm not, I'm skinnier than you!
The argument is ridiculous, of course, but it turns a statement into a fight, usually getting away from the original statement altogether.
Ecological fallacy: Making inferences about individuals, based solely upon aggregate statistics for a group to which he or she may belong. For example:
The man is a snob; he's French, and 78 percent of Frenchmen are snobs.
Even if it were true that most French were snobs, the man in question is an individual, and judging him based upon people who look like him or speak his language is silly.
In a pinch – when we must choose immediately and no precise information is available – we may have to guess based upon statistics. But those are just unfortunate necessities, and in them we must still remember that we're making a wild guess and could be wrong.
Etymological fallacies: Believing that the original or historical meaning of a word or phrase is the same or similar to its present-day usage.
How someone used the word in 1770 doesn't meant the person using it now means it the same way, or even that he should. You can't interpret modern usage with historical usage. The meanings of words change from time to time; their use even changes from person to person.
Words are tools we use to transfer ideas, and they are only tools. They are not to be treated as if they have a rigid, concrete existence of their own.
Fallacy of composition: Assuming that something true of a part of means that it's true of the whole.
Someone using this argument might, for example, tell you why one division of a school or company is magnificent, and then imply that the other parts of the school or company are great. But, that's a false conclusion: there's no guarantee that the other parts are as good as the first. Likewise, one bad part doesn't make the other parts bad. Maybe they are and maybe they aren't.
False attribution: Appealing to an irrelevant, unqualified, unidentified, biased or fabricated source in support of an argument.
This, sadly, goes on all the time, especially at formerly respected information sources like news networks. In our time especially, sources must be checked if we are to base opinions (and especially responses) upon them.
Half a century ago vetting information was a bit easier (news outlets that used bad sources would lose their audience), but nowadays they care very little. With propaganda everywhere, sourcing barely matters, and without "anonymous sources" a great deal of "the news" wouldn't exist.
Fallacy of quoting out of context: It's easy to take one line from an interview, put it together with another line or two, and make it say almost anything you want. What's said before or after gives meaning to any quote, and what a person intended to say is the things that matters. All of us have tripped over our words at various times, and all of us have said things poorly.
Quoting out of context, unless it be an honest accident, is barbarism wrapped in intellectual clothing.
Historian's fallacy: Assuming that people in the past had the same information that we do now. For example, condemning people of centuries past as especially foolish, because they believed things we know to have been wrong. They didn't know and should be judged accordingly.
More than that, if the majority acted in a specific and foolish way some centuries ago, a majority of people in our time, in the same situation, would very likely do the same.
Moving the goalposts: An argument in which evidence presented in response to a specific claim is dismissed and additional on other evidence is demanded. For example:
Hey, look, I've met the criteria to show that this works.
No, you have to provide more proof.
This fallacy became popular in certain scientific circles with the phrase, Extraordinary claims require extraordinary evidence. That, however, is not only a clear case of moving the goalposts, it's also massively unscientific. Who, after all, gets to decide what is to be accepted with normal evidence and what requires extraordinary evidence? Science was formed precisely to eliminate such things. The motto of the first modern, scientific group (that became The Royal Society) was nullius in verba: "Take nobody's word for it."
More next time.