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?
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?
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