What logical fallacies is he using?

[Neutral Milk]

From the wall of the facebook "Got Subluxation" group:

"Just a thought.
Are any of you familiar with Scurvy? Scurvy is a vitamin C deficiency, and back in the 1600's and 1700's many sailors died from Scurvy. Then one day someone noted that the sailors eating limes and lemons where not getting scurvy, so they put limes and lemons on the entire British fleet without knowing the science of why it worked only knowing that it did work. It took science almost 100 years to figure out that it was being deficient in vitamin C that caused Scurvy and that Limes and Lemons had this important vitamin. My question is this. If they waited for science to tell us why and how limes and lemons worked, how many more sailors would have died?
I am not sure about you, but I do not need the science to prove that chiropractic works, I just know it does! I have seen it help so many people who had given up on traditional medicine because the science had failed them."

The argument is obviously silly at best, but what logical fallacies is he using specifically?

[Paul Ganssle]

Argument from ignorance is the obvious one.

He is also using the unstated major premise that chiropractic has been shown to work by saying that people noticing that scurvy was prevented by eating citrus fruit is the same as what chiropractors do.

[Paul Ganssle]

Also, I am not sure how to qualify "I just know it does" as a fallacy.  The closest I'm thinking is the catchall non-sequitur, because that is an unsupported conclusion which does not follow from the premises.

Also, I am also not sure the name of the fallacy, but he is basically using Pascal's Wager here as well, because he is implying that if we DON'T just assume chiropractic works, we are essentially killing thousands of people, and so we shouldn't bother verifying it with science.  Maybe appeal to emotion?

[wallet55]

Argument from ignorance is the obvious one.

He is also using the unstated major premise that chiropractic has been shown to work by saying that people noticing that scurvy was prevented by eating citrus fruit is the same as what chiropractors do.

yes, i think you are right. Very careful and reproducible experiments were done with citrus and scurvy. The effect was so profound and immediate and testable that there was little question about it. However, let us be a little humble here, the truth is most of today's drugs, even the ones we test today are being tested exactly the same way, that is to say, we do not really know how they work, we are only measuring the results.

All the experiments with chiro have turned up no real evidence.

[Zam]

I think it's begging the question. He is assuming that the evidence shows that fixing sublaxations (or whatever) actually does cure disease. If this were correct, then his argument would be right. The part he is ignoring is that unlike the lemons, it doesn't work.

edited to add: It could also be an Unstated Major Premise.

[Kayto]

Also, I am not sure how to qualify "I just know it does" as a fallacy.  The closest I'm thinking is the catchall non-sequitur, because that is an unsupported conclusion which does not follow from the premises.

Also, I am also not sure the name of the fallacy, but he is basically using Pascal's Wager here as well, because he is implying that if we DON'T just assume chiropractic works, we are essentially killing thousands of people, and so we shouldn't bother verifying it with science.  Maybe appeal to emotion?

I think non-sequitur as well.... and for the same reason that you have already stated.

[cosmicvagabond]

I think there's also an element of Post-hoc ergo propter hoc: "I've seen people get better after chiropractic treatment, therefore it must have been the treatment that made them better".

[Joe Shmoe]

All of 'em

[heliocentricra]

Also, I am not sure how to qualify "I just know it does" as a fallacy.  The closest I'm thinking is the catchall non-sequitur, because that is an unsupported conclusion which does not follow from the premises.

That's a really common one in a lot of TB circles, especially with regards to prayer and alternative medicine. Maybe we need to invent a new fallacy for it. You're a cunning linguist, Paul. How do you say "I just know it does" in Latin?

[Joe Shmoe]

Argument from Irrelevant Certainty

Argument ad Gnosticism (for the pun!)

Argument from Omniscience

[Paul Ganssle]

Also, I am not sure how to qualify "I just know it does" as a fallacy.  The closest I'm thinking is the catchall non-sequitur, because that is an unsupported conclusion which does not follow from the premises.

That's a really common one in a lot of TB circles, especially with regards to prayer and alternative medicine. Maybe we need to invent a new fallacy for it. You're a cunning linguist, Paul. How do you say "I just know it does" in Latin?

I don't know.  That seems like too much of a colloquium for me to translate.   Though actually, I was thinking about how to translate it, and I thought the best way to emphasize the way it is fallacious would be to say it as "scio propter scio", meaning "I know because I know".  But when I rephrase it that way, I am thinking it is a tautology.

[Zam]

Unjustified major premise?

[skidoo]

Most of his argument is an attack on a straw man: "If they waited for science to tell us why and how limes and lemons worked, how many more sailors would have died?"

It's not that critics of chiropractic don't understand enough about how it works. That's ridiculous. We don't think it works *at all*.

Then several more logical fallacies follow in quick succession, as others have already noted.

[Joe Shmoe]

Most of his argument is an attack on a straw man: "If they waited for science to tell us why and how limes and lemons worked, how many more sailors would have died?"

It's not that critics of chiropractic don't understand enough about how it works. That's ridiculous. We don't think it works *at all*.

Then several more logical fallacies follow in quick succession, as others have already noted.

There's definitely a straw man in there, but the way you phrase it is more of an argument from final consequences.  i.e., if chiropractic is right and we ruin it because we're a bunch of cynical pricks how many more would suffer?

[Paul Ganssle]

Most of his argument is an attack on a straw man: "If they waited for science to tell us why and how limes and lemons worked, how many more sailors would have died?"

It's not that critics of chiropractic don't understand enough about how it works. That's ridiculous. We don't think it works *at all*.

Then several more logical fallacies follow in quick succession, as others have already noted.

There's definitely a straw man in there, but the way you phrase it is more of an argument from final consequences.  i.e., if chiropractic is right and we ruin it because we're a bunch of cynical pricks how many more would suffer?

That's not a teliology in the strict sense.  That's closer to an appeal to emotion ("You shouldn't ask us to test this because of who you could be killing!") and an unstated major premise ("They will die without chiropractic.").  Argument from final consequences is when you say, "If it is true that there is no god, then there is no afterlife, and that would suck, therefore, there is a god."  If he said, "If chiropractic were not real, I would lose my business, therefore chiropractic is real.", that would be a teliology.