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Posts Tagged ‘logical fallacies’

Evolution, huh? Then where’s my crocoduck?

It’s absurd to suggest that primary school children should get any kind of sex education. Kids shouldn’t be watching porn until they’re old enough to find it for themselves on the internet.

Any psychics in the audience, please raise my hand.

Sometimes it’s really hard to argue properly against someone, especially when they’re making a lot of sense and presenting lots of supportive facts, and even more so if you yourself happen to be full of shit. But the great thing about logical fallacies is that you can quite merrily argue against someone else, someone with a much less defensible position, and still claim a victory.

Sounds so much easier than actually responding to your opponent’s points with sincerity and understanding, doesn’t it? Particularly when the someone else you’re arguing against doesn’t even exist, and is a mere hypothetical construct entirely conjured up by yourself, for the sole purpose of smacking them down and calling your real opponent a failure.

A straw man is just such a construct. Pretend that your opponent’s position is something different from what it actually is, and explain why they’re wrong for believing something that they don’t really believe.

It’s a popular one with creationists who misunderstand (willfully or otherwise) the claims of evolutionary science, and assert that the lack of any dogs seen giving birth to cats undermines anything Darwin might ever have written. (Actually, evolution doesn’t predict this should happen; in fact there’s nothing in the entire field of biology which could possibly explain something so bizarre.)

And it’s something which skeptics need to be careful of when questioning people’s unlikely-sounding claims about, say, paranormal abilities. Maybe it does seem strange how few psychics have ever won the lottery, but it could be that we’re just misunderstanding the nature of the claim, in the same way the creationists are.

This is why Randi is always so painstakingly scrupulous about getting a detailed description of exactly what an applicant says they can do, and under what conditions, before testing them for the Million Dollar Challenge – to paraphrase one of his own examples, it’s no use trying to prove that someone isn’t really a musician by sitting them down at a piano and demanding some Beethoven, if they claim to be a flautist.

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This is another updated and altered version of something I wrote a while ago. It was initially kicked off by a creationist article, where some guy boringly repeats yet again the tedious fallacy that evolutionary processes can be equated with moral decisions.

If you are an “evolutionist” – which I think means, if you are persuaded by the evidence that replication with random variation in a competitive environment is the most likely explanation for the observable variety of living organisms in the world – then, apparently, it necessarily follows that those creatures which are “fitter” than their rivals in some evolutionary sense are also morally “better”, and biology is the only thing that can give us any ideas of moral “goodness”.

This is what’s technically known as “retarculous fuckwittery”.

The idea of evolution is pretty scary to some people, so closely associated as it is with a meaningless, godless worldview. The idea that an entirely natural process could be how the entire human race came about, that we weren’t created specifically by any god and really aren’t all that special in the grand scheme of things, has a lot of big implications, which can be a lot to take in if it’s not an idea you’re used to. The fallacy known as the “argument from final consequences” will get its own entry in the Skeptictionary in time, but it’s clear why so many would feel compelled to reject evolution on the basis of the unthinkable things which seem to result from it.

But science is about studying the way the world works, identifying things that happen, and examining the question of how they happen. It’s about facts. Evolution is a fact. It’s not like we haven’t observed it taking place quite a bit. And even if for some reason you don’t buy that idea, you can at least grasp that the theory is a description of what scientists believe happens.

Which has bugger all to do with what may or may not be good.

It entirely misunderstands science to claim that, because research has been done and the world seems to work a certain way, our sense of morality should be blindly and arbitrarily defined by the principles that scientists “hold dear”. It’s like expecting that anyone who accepts the theory of gravity will spend their time frantically nailing everything to the floor, to stop objects from blasphemously moving upwards.

The fact is, there’s this thing called down, which is where stuff tends to fall. That’s just how the universe works. Any moral decisions are an irrelevancy in noticing this trend. It’s not that they shouldn’t go up, by any moral or ethical mandate, but the application of a downward gravitational force is just what happens.

And another thing about how the universe works, is that when there is replication among a population of entities, mutations in replication that cause variation among them, and differential fitness providing competitive pressures based on specific attributes of those entities, there will happen to occur processes of Darwinian natural selection. It’s just what happens.

Morality is a whole different study. Encouraging something not entirely in line with these Darwinian principles is no more immoral than doing star jumps and yelling “Suck it, Newton!” And doctors who acknowledge evolution, which is what that original Answers in Genesis article was about, aren’t “working against the driving force of nature”. They’re dealing with the Shit that proverbially Happens, and trying to make things better. Not more natural, not more in line with the laws of thermodynamics – those can look after themselves. Just more appropriate, and more desirable, based on things like compassion and humanity. Scientists can hold those dear, too.

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It’s logical fallacy time, here in Skeptictionary corner.

An argumentum ad hominem might look like this:

Is a convicted drunk driver really qualified to comment on a matter of such importance?

Since when did we start listening to suggestions from communists on how to improve our healthcare system?

You’re wrong because you’re an idiot.

It’s an attempt to discredit an argument, by attacking the person (the hominem in “ad hominem“) who is making it, rather than the logic of the argument itself. It’s fallacious because it’s irrelevant; it doesn’t matter who is claiming something, the facts are what’s important in deciding what’s true.

For instance, I hope to get around to discussing the authenticity of the Bible on this blog before long. If you want to defend your Holy Book, it’s not going to do you any favours to rant about how a godless heathen like me can’t be trusted, or to bring up those baby seals I hunted to death that one time, without actually addressing my points. The historical evidence stands as it stands, regardless of my personal history.

And, fair’s fair; if someone brings up a point about Biblical prophecy or some such which they think supports the Bible’s divine origins, it doesn’t help me to simply declare that nobody so blinded by ideology could possibly have anything useful to say. An argument should be judged on its own merit, and irrelevant ad hominem arguments don’t advance anyone’s cause.

They tend to come in three (or maybe four) flavours:

An abusive ad hominem is a straight-forward insult or an aspersion cast against your opponent, in an illogical attempt to damage the logic of their own standing. (“Sure, he sounds like he knows what he’s talking about, but can you ever really trust a convicted jay-walker?”)

A circumstantial ad hominem is something I’ve seen described in two different ways. It can be an attempt to undermine someone’s credibility, and thus the credibility of their argument, by pointing out an apparent source of bias. (“Of course he says women should get paid more; he needs the women’s vote to get elected.”) It may also be a way of encouraging acceptance of a claim based on your audience’s personal biases, rather than on the facts that support or refute it. (Asking “What would Jesus do?” only has a chance of being persuasive to a certain demographic of the population.)

And a tu quoque (“you too!”) argument is an attempt to undermine the reasoning of an argument by accusing its opponent of acting inconsistently with it. (“If Al Gore’s so worried about the environment, why does he keep flying around on his private jet to tell us all about it?”)

Making accusations about a speaker’s character isn’t always irrelevant and inappropriate, though. Climate change either is or isn’t a problem we should be doing something about, regardless of Al Gore’s personal carbon footprint – but if you wanted to make the case that Al Gore is a hypocrite, then this would be a relevant point to bring up, even if it doesn’t make him wrong about our impact on the environment. Similarly, gender equality seems to be a fine thing, whatever any politicians are saying – but a claim that can’t be objectively verified, which relies more on the arguer’s personal opinions or authority (“You should vote me, because I’ll do something about this”) can reasonably be called into question by bringing up their personal biases.

And, so long as you’re not confusing it with logic, sometimes hurling abuse at people is just fun.

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Isn’t it annoying how, when you’re having an argument with someone, they keep demanding that you make sense, or expecting you to explain yourself, or telling you that your position has no basis in reality? Like, when you’re pointing out how that Obama guy’s definitely a Muslim, but people keep bringing up those Christian churches he went to for years and all those things he’s said about being a Christian, and completely ignore that one time it looked like he was wearing a turban? Doesn’t that just piss you off?

Some people are just sticklers for sound logic that way. A logical fallacy is some type of argument which doesn’t work, and can’t reasonably be used to support the proposed conclusion. This section of the Skeptictionary is going to be about the various types of logical fallacy that people constantly use, often without really being aware of it. These are important to understand, and to avoid as much as possible, for what I hope are obvious reasons. If you’re trying to persuade someone else of your correctness, and you’re having to use manipulative strategies and faulty logic to do it, then maybe what you’re arguing ain’t so great. And if you don’t know how to spot a fallacious argument, then you’re in a pretty weak position to judge when someone else is taking you for a ride.

Arguments that try to sound persuasive, without actually invoking logic or making any sense, may look something like this:

“Have you examined every photo of an alien spaceship ever and proved that every one of them is a fake?”
“If you let them gays get married, next year you’ll be legally obligated to go on a honeymoon with your dog!”
“I’m just too ahead of my time for you to understand me. They laughed at Einstein too when he invented the speed of light.”
“It’s not a horse, it’s a unicorn! His horn’s only visible if you really believe in him!”
“You know who also wanted universal healthcare? Communists.”

It’s a useful skill to have, to understand why these kinds of arguments shouldn’t persuade us. Otherwise we could end up basing our political opinions on some irrelevant nonsense, or giving money to nutcases for pointless scientific research because they think they’re the next Einstein, or rallying against a good idea just to avoid being painted with some undesirable label.

So, this section of the Skeptictionary is going to detail some of the wonky arguments to watch out for, and to call people on when you see them being used to try and convince you of something.

Anyway, you know who gets taken in by logical fallacies? Communists. You’re not a communist, are you?

(What are we thinking of the name “Skeptictionary”, by the way? I was also toying with Rationalmanac, but I’m not wholly convinced by either. Suggestions welcome.)

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Some brief thoughts on this, simply because I’ve written about it before, and it’s a less intimidating task to redraft an old piece and attempt to make it interesting than to start something new from scratch.

So, there are people who claim that every word of their particular edition and translation of the Bible is absolutely true, and thank Jesus daily for the mysterious and divine processes through which everyone who disagrees with them about anything is totally wrong. A lot of them won’t even qualify the word “true” with more than the scantest of ifs and buts, either. Some will attempt to compromise more than others, by talking about allegory and metaphor, but all that usually focuses on the trippy stuff near the beginning. People still want to be able to call the creation story “true”, even though it places the age of the Earth at around six thousand years, and some things (eg. pretty much everything in the Universe) seem to have been around for longer than that. But I’m not going to address any of that here, or bring pesky “evidence” and inconvenient “facts” into things. I just have an observation about the way people often attempt to reconcile the stuff that contradicts the other stuff.

Using the Skeptic’s Annotated Bible edition, Matthew 27:5 reads: “And he cast down the pieces of silver in the temple, and departed, and went and hanged himself.

And Acts 1:18 reads: “Now this man purchased a field with the reward of iniquity; and falling headlong, he burst asunder in the midst, and all his bowels gushed out.

Ew. They encourage kids to read this stuff, you know. Both of these passages are about the death of Judas, the guy who took the “thirty pieces of silver” idiom way too literally when he betrayed Jesus, and who then went on to marry Mary Magdalene, father the bloodline of Leonardo da Vinci, establish at least eight secret societies which would rule the world two thousand years later, and hide the Holy Grail in Castle Anthrax. (I think it was something like that, anyway. I may have dropped some acid when I watched the Da Vinci Code movie. Good times.)

There would seem to be some problems for the literalists here, inasmuch as reality is ever a problem for these people. The first one says he hanged himself, and the second… I dunno, maybe he tripped and fell on something pointy. Obvious contradiction, no?

Well, not necessarily. The standard justification for protecting people’s minds, and defending against the inconceivability of such a horrifying notion that the Bible might be wrong about something, is to contrive a death scene which, in however roundabout a way, satisfies both of the descriptions given. Judas hanged himself, he died, the decomposition process caused his body to become bloated and corpulent, the rope around his neck frayed and snapped, and he fell to the ground and his guts burst open. Don’t think it couldn’t happen, people. (Seriously, I don’t know much about what would happen to a human body post-mortem in a situation like that, but this sounds plausible enough to me.)

It could even be argued that Matthew never actually claims that Judas died as a result of the hanging – maybe his first attempt failed, so he went and threw himself over a cliff, which could have counted for “falling headlong”, I guess. Either way, it all adds up. Praise the Lord, thank-yoo Jay-sus.

Except… not really. That’s some non-trivial verbal gymnastics we’ve had to go through to make this idea work. The scenarios that we’ve come up with to explain it, while plausible, are both significantly different from what’s actually described in either passage alone. If you just read Matthew, it makes it seem very straightforward: he hanged, he died, no gushing of bowels necessary. But looking only at Acts would lead you to a whole nother picture of what happened to him, leaving out any kind of noose system entirely, and giving Judas some kind of scary Jon Hurt moment, or perhaps just sudden, fatal, explosive diarrhoea.

It seems that we’re being given unhelpfully contradictory clues scattered throughout the complete text, and are left with the challenge of fitting the pieces together ourselves into some sort of coherent structure, requiring an excessively generous dose of deductive logic to do so. It might not be irreconcilable, but it doesn’t help your case when you need to work from the assumption that everything you’re reading is true, and then make stuff up to keep this assumption feasible.

Damn near anything could probably be worked into a coherent scenario with enough mangling of the text, if you’re willing to do some heavy-duty text-mangling to keep your belief system safe. If there was an additional mention of the event somewhere in Luke, say, which described Judas as being burned alive in a giant Wicker Man, then I have no doubt that someone, somewhere, would be claiming that this was a reference to some specific funereal tradition of the time, and that the word “alive” refers to the idea of the soul needing to be released from the body by this ritual, or possibly even something more plausible than the first crazy shit that sprung to my mind. If John claimed that Judas was eaten by velociraptors, then I would totally become a Christian and make this the basis of my entire belief system, and I would concoct as elaborate an explanatory scenario as necessary to convince myself of its truth.

But if you’re going to think like this, then there’s nothing that could possibly prove you wrong, or undermine your position in any way, however much it supports an alternative explanation to the one you favour. And thinking as inflexibly as this is never good, because on the off-chance that you are wrong to begin with, you’re screwed. Even if you decide not to see anything in the Bible as an internal contradiction, then passages like the above certainly shouldn’t lead you to the idea that it supports itself. The convoluted explanation for how Judas died isn’t backed up anywhere else, by any description that directly suggests that that’s what happened, let alone by anything actually credible. Even if you choose not to see it as an inconsistency, something requiring such lateral-thinking problem-solving as this ought to raise a red flag or two, and make you wonder whether there’s enough of a reason outside of this passage to take the contrived work-around seriously.

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