Item 1
Joan is scratched by a cat
while visiting her friend. Two days later she comes down with a fever. Joan
concludes that the cat's scratch must be the cause of her illness.
Analysis:
Premise 1: Joan is scratched by a cat.
Premise 2: She comes down with a fever.
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Conclusion: The cat’s scratch makes her ill.
=> Post-hoc fallacy
There is no causal relationship between the cat’s scratch and
Joan’s illness. It can be true if after being scratch, Joan was in completely
sterile condition.
Item 2
Analysis:
Premise 1: Saddam committed 9/11.
Hidden premise: The
event 9/11 is a disaster, Saddam is dangerous.
Premise 2: Bush caught Saddam.
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Conclusion: Bush made America safe.
=> Hasty generalization:
Assuming that safe is only without terrorists. Moreover, “safe” itself is an
ambiguous word.
Item 3
Analysis:
Premise 1: Two is a number
Premise 2: One is a number
______________________
Conclusion: One is two
=> Structural fallacy
All S are P
a is P
_________________
Therefore a is S
Source: http://niyamaklogic.files.wordpress.com/2009/05/fallcy.jpg?w=220&h=167
item 3: i think it's not the structural fallacy you've analysed but it has a hidden premise: different numbers have different values. So 1 does not equal 2
Trả lờiXóaIn item 3, I agree with Hanh. It is structural fallacy
Trả lờiXóaIn first item, fallacy should be hasty generalization in stead of post-hoc. Because, in fact scratches by cat can cause rabies, and fever is one of symptoms of cat rabies. That's why the conclusion of Joan about her sickness (before aksing doctor) may be hasty.
Trả lờiXóaAs far as I know, only a cat's scratch cannot cause rabies. If the cat did not bite you and its saliva did not get into your bloodstream, it is unlikely you would get rabies.
Xóaitem 3: i gree with Dương Nguyên Xuân, it is the same structure and it has a hidden premise: different numbers have different values.
Trả lờiXóaI think there is a hidden premise in item3: every number has its own value
Trả lờiXóa