Logical fallacies

As the hardest thing about declaring someone’s use of a logical fallacy is actually matching their argument to a canonical example of a fallacy, I will present some examples here of arguments that I have actually heard used, rather than just repeat a list of the classics. Hopefully in doing so I will prove how common they are in debates and how useful it is to know them. Of course, I would like to think that everybody knew of these logical fallacies, by name even, and would retract their argument when it was rightly pointed out to be fallacious. I know this is unrealistic, but fortunately it suffices that my knowledge of them helps me to not make bad arguments and to respond better when exposed to them. Here then is the list:

“… one should ‘earn the right’ to criticise by first having contributed to the thing you are criticising.”

As pointed out in an earlier post, this is an example of the ad hominem circumstantial fallacy.

“You can’t ask them to be more clear when you yourself are not perfectly clear”

Also pointed out in a previous post, this is an example of the ad hominem tu quoque fallacy.

“… but to be honest though if liniux because [became] the main user OS and it because [became] popular …” then it would suffer from more viruses and other malware

There is of course an argument that the more popular an operating system, the more it is a target to malware writers, but the desire for something to be exploited doesn’t change the underlying possibility of it happening. The more people hear about time travel, the more it is desired, but that doesn’t change whether it is actually possible. It could be that Linux is already being exploited to its theoretical maximum amount and that no amount of increased popularity will change that (unless popularity leads to worse code in Linux, invalidating Linus’s law). The underlying flaw here is the logical fallacy cum hoc ergo propter hoc.

“You haven’t shown me a secure, popular Linux, therefore one cannot exist” [paraphrased]

Basically a restatement of the previous argument, but it highlights a different fallacy, namely argument from ignorance. Instead of proving that Linux being more popular would somehow lead to less secure code or to the same level of insecurity being exploited more, it puts the burden of proof on the defender. Even if a secure, popular Linux hasn’t yet been shown to exist, the burden of proof is on the one who claims that such an operating system could never exist.

“pwople say OSX never crahses or anything but ive seen it” [as an argument against Linux security]

This is a wonderfully flagrant example of a straw man argument. The attacker did not feel they were making any headway against Linux, and therefore tried to deal with all the arguments in support of Linux collectively, by comparing them to one argument in support of OSX which they knew they had a counterargument for. Unfortunately for them, this has no bearing on Linux security apart from the pointing out the truism that people are sometimes mistaken about the relative merits of operating system. (I should point out here that I am exceedingly grateful to my friend for having what was a very light-hearted discussion with me about operating systems, with neither of us particularly fanatical about our positions. More importantly, I should point out that some of this conversation was going on at past 01:00 in their timezone and possibly mine. I would not want my criticisms of specific arguments to suggest that I didn’t fully respect this person’s technical knowledge.)

“If you see [Microsoft’s plan to provide the ‘Microsoft Student Innovation Suite’ for $3 to governments around the world, for use in schools] as a conspiracy , you really have to consider what the *real* goal of [the] OLPC [project] is.”

This is perhaps the most useful of these examples, which comes from an actual public discussion about two projects to give students in certain countries access to computers. A contributor to the discussion put forward a series of arguments and assertions in support of Microsoft’s actions and in favour of governments accepting their offer. In response to this, another contributor put forward an intelligent and helpful rebuttal, leaving off one detail when, to counter the above sentence, they wrote “That’s a logical fallacy, although I’m too lazy to go look up which one it is.” Well fortunately the open source model doesn’t rely on people not being lazy, or forcing lazy people to work through fear of getting sacked, it relies on many eyes and people scratching their own itches. The absence of a name for this fallacy (while not, I think, weakening the rebuttal) made me itch, so let me try scratching it: That conspiracy argument is basically saying “The Microsoft plan and the OLPC project are similar; you think that Microsoft must be doing this for evil purposes therefore the OLPC must be doing this for evil purposes.” If that characterisation is accurate, then I believe the Microsoft supporter has made the fallacy of weak analogy.

[Warning: If taken seriously, the following argument is sickening in its callousness and ignorance] “[Violence is sometimes the answer] … look at hitler for example[,] everyone was a jew [and] now theres like 10”

I am sad to say I had the misfortune to actually hear that argument being used. Clearly the person making the argument knew there was some level of exaggeration in it, but I am sure they did believe there was an element of truth to it. Strangely, though, this person was not anti-Jewish and was not supporting what people had done under Hitler’s regime. The sad truth is that they were just ignorant of a few facts, even being surprised when I said I had seen some Jews within the last two months. I am personally more worried about the fact that they were supporting violence as the principle answer to problems in societies, even though they gave me the minor assurance that they were not capable of violence themselves. If this argument were not anything other than a big mistake, then it would have been the logical fallacy (or debating strategy) of “a red herring”. One cannot begin to point out what is wrong with their statement, even once one has recovered from the shock of hearing it, and despite losing all one’s credibility making it, it would buy one some time in a “debate to win” contest. Coincidentally, my initial choice of words in confronting this argument was to call it a “canard”, which I quickly looked up to check I had the correct terminology. According to Wikipedia, this choice of word was more than accurate.

There’s quite a list there, which perhaps shows that these problems are common and varied. This is a little worrying, and makes me wonder how well informed people are when they make decisions about the big issues like religion and politics. The other question is “Do people think that increasing their ability to make correct logical judgements and avoid logical fallacies is worth the effort?” Maybe people confuse strength of belief with the validity of those beliefs, thus not seeing any need to examine their strong beliefs or in some cases others’ strong beliefs.

How much effort should one put into proving oneself wrong? At least as much as proving oneself right?