Name that logical fallacy

Heisenberg

Well-Known Member
I'm going with argumentum ad antiquitatem for $500...
You are technically correct. All the sources I look up combine argument from antiquity with appeal to tradition. In my mind they are different. Argument from antiquity argues something is true based on it's history of use, i.e. Women must be inferior to men as evidenced by their history of not doing things other than housework and mothering. Appeal to tradition ignores the truth value and simply says something should be continued because it has been for so long, true or not, i.e. women may be equal but their place has always been in the home and should stay that way.

I am giving you an A but I have my eye on you.
 

Heisenberg

Well-Known Member
1) John was a marathon runner. After starting to drink wheat grass juice John had the best marathon time of his life by far. The next race was not as good, but still better than usual. Soon John was finishing at his normal time again despite continuing his juice drinks. John concludes the wheat grass had an effect on his performance until his body became used to it.

2) John had back pain, but on most days it was bearable. One particularly bad day he could take no more and drank a homeopathic remedy his neighbor offered. His pain returned to normal levels the next day, proving the treatment worked.

3) John was married to Jane, both were exceptionally tall. Their children, although taller than average, were not nearly as tall as either parent. Based on this, John concludes Jane cheated on him and he is not the father.


Remember the fallacy must apply to all three.
 

cannabineer

Ursus marijanus
Ahh but the last one does not argue that because the children were born Jane cheated, or employ any sort of 'after this' logic. It's reasoning lies elsewhere.
Oh dear. I must have only glanced at that third. And I don't wanna say it's cum hoc, as I have no assurance that Jane purchased the sperm at a bank.

Seriously, I am going with the statement that cum hoc would apply, since it's a correlation/causation fallacy like the two post hoc examples. cn
 

tyler.durden

Well-Known Member
Oh dear. I must have only glanced at that third. And I don't wanna say it's cum hoc, as I have no assurance that Jane purchased the sperm at a bank.

Seriously, I am going with the statement that cum hoc would apply, since it's a correlation/causation fallacy like the two post hoc examples. cn
Don't feel bad, Neer, he got me with a similar one. All the examples are non sequitur, so that's my final answer...
 

Heisenberg

Well-Known Member
The mistake John makes in each case is ignoring the regression to the mean. Anytime we have a baseline established and then a certain data point lies away from that baseline, our brains see a pattern. The further away the data point, the more we want to assign a cause. In addition, the further away the data point, the more likely subsequent data points will be closer to the average than to the exception. This fallacy is committed when we assign arbitrary reasons for the return to mediocrity, rather than acknowledging that it is expected.

1) Notice John does not just attempt to explain his exceptional time with wheat grass juice, he is also trying to explain why he did not continue having exceptional performance even though he continues drinking juice. His return to an average time is evidence that the wheat grass did nothing, but rather than abandon his original mistake, he explains it away with a further assumption.


2) If the remedy worked we would expect the pain to vanish, not simply return to a previous average level. The presence of pain indicates the cause has not been treated. It is much more likely that the pain would return to its baseline on its own, in fact, that is what we expect.


3) The more exceptional John and Jane's height, the less likely their children are to equal or exceed that exception. We do expect tall parents to have tall children, but if all children reached the height of their parents then John's height wouldn't be exceptional. The taller the parents are, the more likely their children will be closer to average than to the exception.
 

Heisenberg

Well-Known Member
Awesome. I fell prey to this fallacy many times, but never identified it as such. Keep 'em coming, Teach...
BTW tyler you were correct that they are all non-sequitur, as all formal fallacies are. The term non-sequitur, meaning 'does not follow', is normally used when an argument does not have a specific flawed mechanism for reaching a conclusion, but simply combines two non-logically connected ideas.

John eats a lot of red tomatoes, he must live in a very red house. <-- There is no specific mistake being made, it just does not follow. Stated this absurdly it is easy to spot.

Here is one a bit more convincing.

Millions of people have seen unidentifiable lights in the sky. Alien visitation is certain. <-- This may appear to be making an appeal to popularity, but those millions of people have not concluded anything, or at least their conclusions are not mentioned. This also may appear as a false dichotomy, however the argument is not considering even two options (human/alien), but just the one. It never follows that something having the property of unidentifiable can be identified by that very same property, even if it is the case a million times over.
 

mindphuk

Well-Known Member
3) John was married to Jane, both were exceptionally tall. Their children, although taller than average, were not nearly as tall as either parent. Based on this, John concludes Jane cheated on him and he is not the father.

The more exceptional John and Jane's height, the less likely their children are to equal or exceed that exception. We do expect tall parents to have tall children, but if all children reached the height of their parents then John's height wouldn't be exceptional. The taller the parents are, the more likely their children will be closer to average than to the exception.
I think this one gets me. Although regression to the mean is expected, part of the problem is that we know that height is passed down through genetics, and for me, that implies tall children and I don't think my brain parsed the key word, "exceptionally" even after multiple readings. It's almost as if my brain ignored it while trying to justify accepting the fallacy along with John. Weird.
 

cannabineer

Ursus marijanus
I think this one gets me. Although regression to the mean is expected, part of the problem is that we know that height is passed down through genetics, and for me, that implies tall children and I don't think my brain parsed the key word, "exceptionally" even after multiple readings. It's almost as if my brain ignored it while trying to justify accepting the fallacy along with John. Weird.
I had the same thing happen. It was the word "unidentifiable" in one of the examples ... my brain swapped in the more usual "unidentified", which weakens the non sequitur. cn
 

Heisenberg

Well-Known Member
1) John is an investigative reporter researching rabies. While reviewing data, John notices a certain town has a much higher rate of rabies among it's animal population than chance calls for. John concludes this town is purposely spreading rabies among it's animals.

2) John is also a ghost hunter in his spare time. John believes electromagnetic anomalies are evidence of ghost activity. He searches all the abandoned houses in his neighborhood and finds one with a high level of electromagnetic activity as compared to the others. He buys this house and declares it the most haunted in the neighborhood.

3) When we look at life we see incredible complexity arise from randomness. The chances of a protein, a cell, a frog, or even the universe forming randomly out of chaos is near nonexistent. We must have a designer.


Not an easy one. All of these essentially make the mistake of not investigating further, or begging the question, but each has a specific mechanism in common.
 

Dr Kynes

Well-Known Member
Coincidentally Jane did in fact cheat, but it was with John's sister, so there was no chance of pregnancy.
ooooOOooOO!! '

i think you need to explain this in greater detail.

SLOWLY!

and use the term "Heaving Bosoms" a lot.

yeah... just like that...
 

Dr Kynes

Well-Known Member
1) John is an investigative reporter researching rabies. While reviewing data, John notices a certain town has a much higher rate of rabies among it's animal population than chance calls for. John concludes this town is purposely spreading rabies among it's animals.

2) John is also a ghost hunter in his spare time. John believes electromagnetic anomalies are evidence of ghost activity. He searches all the abandoned houses in his neighborhood and finds one with a high level of electromagnetic activity as compared to the others. He buys this house and declares it the most haunted in the neighborhood.

3) When we look at life we see incredible complexity arise from randomness. The chances of a protein, a cell, a frog, or even the universe forming randomly out of chaos is near nonexistent. We must have a designer.

Not an easy one. All of these essentially make the mistake of not investigating further, or begging the question, but each has a specific mechanism in common.
are these not also the disjunctive fallacy where irrelevant non sequitors are used to falsely establish an unrelated conclusion?

for example: fish live in the sea. jellyfish also live in the sea, jellyfish are called fish despite their obvious differences from fish fish, so therefore crabs are also fish. and the moon is made of peanut butter and rice crispies.
 

cannabineer

Ursus marijanus
1) John is an investigative reporter researching rabies. While reviewing data, John notices a certain town has a much higher rate of rabies among it's animal population than chance calls for. John concludes this town is purposely spreading rabies among it's animals.

2) John is also a ghost hunter in his spare time. John believes electromagnetic anomalies are evidence of ghost activity. He searches all the abandoned houses in his neighborhood and finds one with a high level of electromagnetic activity as compared to the others. He buys this house and declares it the most haunted in the neighborhood.

3) When we look at life we see incredible complexity arise from randomness. The chances of a protein, a cell, a frog, or even the universe forming randomly out of chaos is near nonexistent. We must have a designer.

Not an easy one. All of these essentially make the mistake of not investigating further, or begging the question, but each has a specific mechanism in common.
I've been wrestling with this one for hours now. i can find commonalities between 2 out of 3, but then the third doesn't conform.

In instance 1, I see affirming the consequent:

a: Deliberate spreading of rabies increases its incidence.
b: Rabies is present in increased evidence at the location.
c(and fallacious): The spread of rabies at the location is deliberate.

I can analyze example 2 similarly, with the improperly affirmed antecedent being that all em activity is from ghosts.

However example 3 does not fit this model. The best I can do with it is denying the antecedent, to wit:

a: We see great complexity (I consider inserting "from randomness" to be a red herring.)
b: Such great complexity is almost certainly not random.
c: Thus, the complexity arose by design.

...I am missing something basic. But I'm not getting a handle on it. cn
 

Dr Kynes

Well-Known Member
I've been wrestling with this one for hours now. i can find commonalities between 2 out of 3, but then the third doesn't conform.

In instance 1, I see affirming the consequent:

a: Deliberate spreading of rabies increases its incidence.
b: Rabies is present in increased evidence at the location.
c(and fallacious): The spread of rabies at the location is deliberate.

I can analyze example 2 similarly, with the improperly affirmed antecedent being that all em activity is from ghosts.

However example 3 does not fit this model. The best I can do with it is denying the antecedent, to wit:

a: We see great complexity (I consider inserting "from randomness" to be a red herring.)
b: Such great complexity is almost certainly not random.
c: Thus, the complexity arose by design.

...I am missing something basic. But I'm not getting a handle on it. cn
that was pretty deep homey. i think i should get more seal blubber in my diet since it's obviously doing good things for you.

also, Klondike Bars.
 
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