• Welcome to Religious Forums, a friendly forum to discuss all religions in a friendly surrounding.

    Your voice is missing! You will need to register to get access to the following site features:
    • Reply to discussions and create your own threads.
    • Our modern chat room. No add-ons or extensions required, just login and start chatting!
    • Access to private conversations with other members.

    We hope to see you as a part of our community soon!

Fun Fun Logic Quiz: What's that Fallacy!

Sunstone

De Diablo Del Fora
Premium Member
What is the informal fallacy of logic perpetrated in the following argument (You can win either by correctly explaining what's wrong with the argument, or by correctly naming the informal fallacy committed in the argument, or by doing both):

1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

Winning entries will be awarded a "winner" frubal after the quiz closes.

EDIT: YES! WE HAVE WINNERS!

In order of appearance: @Scuba Pete , @निताइ dasa , @Revoltingest , @james bond , and @Debater Slayer . All five pointed out that there was an equivocation on the word “doctor”, which is an informal fallacy of ambiguity.

Special mention to @निताइ dasa who also pointed out the fallacy of affirming the consequent, which is a propositional fallacy of presumption.


To explain: The fallacy of equivocation is committed when a key word is given more than one meaning in an argument. For an argument to be valid or at least probable, key words must have the same meaning through-out the argument. This is because changing their meaning is the same as changing the subject. This is, if you use the same word in two or more different meanings, you might as well be talking about two or more different things.

The argument in the OP equivocates on the word “doctor”. In some instances, it means a medical doctor. In other instances, it means a doctor of physical cosmology, which is a science akin to astronomy, and has nothing to do with medicine. Thus, that Dana is a doctor of physical cosmology does not support the conclusion that she knows how to heal people.


Affirming the consequent: This fallacy has the form:

1) If A then B.
2) B.
Therefore, A.

The first step is to note that A has the consequent, B. The second step is to note that B has occurred. The error comes when one then goes further to assume that because B has occurred, A must have also occurred.

Example:

If Scuba Pete is present, then someone is having sex
Someone is having sex.
Therefore Scuba Pete is present.

Questions?
 
Last edited:

Scuba Pete

Le plongeur avec attitude...
1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.
Dicto simplicter: aka hasty generalization. Not all doctors are medical doctors.
 

निताइ dasa

Nitai's servant's servant
I found a formal fallacy if that matters? From a purely logical perceptive Premise 2 is twisted illogically into the conclusion. The problem is made even more confusing by the fact that the term 'doctor' can be used to refer to two different properties (which I'm guessing is the informal fallacy).

To be a doctor you must have a doctors degree does not mean that all those that have a doctors degrees are doctors

Aka affirming the consequent .

X is a doctor => x has a doctors degree

Does not mean

X has a doctors degree => x is a doctor.'

Even if Dana holds a doctorate degree, that doesn't mean she is a doctor (according definitions set forth in the argument).

Just like all 'humans must be mortal' does not necessitate that 'mortals must be human'.


Just want to show off my sweet logic tree skills. :tonguewink:
IMG_0236.JPG


From this is is shown that the argument is invalid (even if the premises are true, the conclusion is not guaranteed: see counter example).

It is interesting actually. Whether actually Dana knows how to heal illness's or not is irrelevant. Rather this argument fails to prove that Dana is a doctor who also knows how to heal (which is the conclusion).
 
Last edited:

Kilgore Trout

Misanthropic Humanist
What is the informal fallacy of logic perpetrated in the following argument (You can win either by correctly explaining what's wrong with the argument, or by correctly naming the informal fallacy committed in the argument, or by doing both):

1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

Winning entries will be awarded a "winner" frubal after the quiz closes.

This was a tricky one! Doctor's don't know how to heal people of illnesses - they know how to write prescriptions for medications which purportedly heal people of illnesses, in addition to giving them diarrhea, headaches, seizures, and sudden death.
 

viole

Ontological Naturalist
Premium Member
What is the informal fallacy of logic perpetrated in the following argument (You can win either by correctly explaining what's wrong with the argument, or by correctly naming the informal fallacy committed in the argument, or by doing both):

1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

Winning entries will be awarded a "winner" frubal after the quiz closes.

There is nothing wrong with the argument or the inference, per se. If all premises were true, then the conclusion would follow.

The problem here is that premise 1 is not true in general.

Ciao

- viole
 

Revoltingest

Pragmatic Libertarian
Premium Member
Assuming the given premises....
The word, "doctor" (like "faith") has multiple meanings.
Using different definitions of the word in the same context
within an argument results in the equivocation fallacy.

Note....
Even we adjust the premises to assume that "doctor" refers solely to medical doctors,
& that Dana has a such a degree, this doesn't lead to Dana actually becoming a
medical doctor. (Not all medical school graduates become medical doctors / healers.)
It's the "association fallacy".
 
Last edited:

james bond

Well-Known Member
What is the informal fallacy of logic perpetrated in the following argument (You can win either by correctly explaining what's wrong with the argument, or by correctly naming the informal fallacy committed in the argument, or by doing both):

1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

Winning entries will be awarded a "winner" frubal after the quiz closes.

1. Deferring to authority
2. The two degrees aren't necessarily the same
3. #2 and conditional fallacy
 

james bond

Well-Known Member
Equivocation fallacy.
It often comes up regarding the word, "faith", which has multiple meanings used
within the same argument, eg, confidence in something, belief without evidence.

What about atheist's fallacy? One can't prove something exists. One can't prove it doesn't exist. Therefore, it doesn't exist.
 

Nous

Well-Known Member
Premium Member
I found a formal fallacy if that matters? From a purely logical perceptive Premise 2 is twisted illogically into the conclusion. The problem is made even more confusing by the fact that the term 'doctor' can be used to refer to two different properties (which I'm guessing is the informal fallacy).

To be a doctor you must have a doctors degree does not mean that all those that have a doctors degrees are doctors

Aka affirming the consequent .

X is a doctor => x has a doctors degree

Does not mean

X has a doctors degree => x is a doctor.'

Even if Dana holds a doctorate degree, that doesn't mean she is a doctor (according definitions set forth in the argument).

Just like all 'humans must be mortal' does not necessitate that 'mortals must be human'.


Just want to show off my sweet logic tree skills. :tonguewink:View attachment 15831

From this is is shown that the argument is invalid (even if the premises are true, the conclusion is not guaranteed: see counter example).

It is interesting actually. Whether actually Dana knows how to heal illness's or not is irrelevant. Rather this argument fails to prove that Dana is a doctor who also knows how to heal (which is the conclusion).
Well done. I can't tell you how much I admire your logic skills.
 

Neo Deist

Th.D. & D.Div. h.c.
What is the informal fallacy of logic perpetrated in the following argument (You can win either by correctly explaining what's wrong with the argument, or by correctly naming the informal fallacy committed in the argument, or by doing both):

1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

Winning entries will be awarded a "winner" frubal after the quiz closes.

Dana did not go to an accredited university, therefore she doesn't know jack crap! Only accredited universities have the right to graduate REAL doctors.
 

Debater Slayer

Vipassana
Staff member
Premium Member
1) Doctors know how to heal people of illnesses.
2) To be a doctor, you must have a doctor's degree.
3) Dana has her doctors degree in physical cosmology.
Therefore, Dana is a doctor who knows how to heal people of illnesses.

I suspect an appeal to (an irrelevant) authority: Dana indeed has a doctorate, but since it's irrelevant to the field teaching how to heal people of illnesses, she might as well not have a degree at all for this purpose. It's like arguing that a professor in engineering could debunk evolution just because he or she has a doctorate.
 

siti

Well-Known Member
Proof by example or inappropriate generalization...premise 1 is faulty because not ALL doctors heal people...
 

Revoltingest

Pragmatic Libertarian
Premium Member
Doctors do not heal people. Nature heals people. Doctors use nature to help people to heal.
But when I once had pneumonia, the antibiotic my doc prescribed sure did help.
And when I had a badly broken leg, the orthopod who screwed it back together
was also really really useful.
So accepting the premise for purpose of the quiz is reasonable.
 

Sunstone

De Diablo Del Fora
Premium Member
YES! WE HAVE WINNERS!

In order of appearance: @Scuba Pete , @निताइ dasa , @Revoltingest , @james bond , and @Debater Slayer . All five pointed out that there was an equivocation on the word “doctor”, which is an informal fallacy of ambiguity.

Special mention to @निताइ dasa who also pointed out the fallacy of affirming the consequent, which is a propositional fallacy of presumption.


To explain: The fallacy of equivocation is committed when a key word is given more than one meaning in an argument. For an argument to be valid or at least probable, key words must have the same meaning through-out the argument. This is because changing their meaning is the same as changing the subject. This is, if you use the same word in two or more different meanings, you might as well be talking about two or more different things.

The argument in the OP equivocates on the word “doctor”. In some instances, it means a medical doctor. In other instances, it means a doctor of physical cosmology, which is a science akin to astronomy, and has nothing to do with medicine. Thus, that Dana is a doctor of physical cosmology thus does not support the conclusion that she knows how to heal people.

Affirming the consequent: This fallacy has the form:

1) If A then B.
2) B.
Therefore, A.

The first step is to note that A has the consequent, B. The second step is to note that B has occurred. The error comes when one then goes further to assume that because B has occurred, A must have also occurred.

Example:

If Scuba Pete is present, then someone is having sex
Someone is having sex.
Therefore, Scuba Pete is present.

Questions?
 
Top