(Common Logical Fallacy in Thinking) HKCC-CCT L9-10 Notes Chinese Version

L09-10 

  () ()()      4 categories of fallacy :   

Fallacies

of Inconsistency 



Fallacies

of Irrelevance 



Fallacies of Insufficiency I nsufficiency



Fallacies



of Inappropriate Presumption 

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

: 

    



  



s  s    

I1  Self Contradiction 1.1

 p  not p  Contradiction is the relation between a proposition  p and its denial not p.

 Peter is reading  and Peter is not reading  1.2

 Contradictory propositions can neither be both true nor both false.

1.3

p  not p p  not p 

* Are The car is black and the car is white contradictory?

:  I2  Self Defeating 1



2

  

!( ) ( )

:  (    ) = 

I3  Double Standard 



 

    



 





: 

  







 

II1  Argument  Ad  Populum 

  p 

p 

:  

II2  Argument  Ad  Hominem 



:   d   II3  Appeal to Inappropriate Authority 

 X   p   

X 



X  





: 1.

  

2.  +    3.  +  

II4  Strained Analogy 



 A   B  

 A  pB  p



   

 

 [  II5   Smuggling a Fake Subject 

  ¿

a) 

Attacking

a Str aw man

 /  

& 



 Red-herr ing

 b) 

' 

  



 A ,  B  A  A  ,   B  A 

 ..  /  /   / } /   /  /  ..  

: III1

Hasty Generalization 



 Inductive Generalization/ 

// : a) (the sample size is too small) b) (there is a structural bias in the sample) c) (there are unfavorable, contradicting findings against the conclusion supposed to be drawn) (Hasty Generalization)

Accident 

III2 



 

 Vehicles should not exceed the speed limit. Since police cars are vehicles, it is obvious that police cars should not exceed the speed limit. 

Composition 

III3 

  



()() Division 

III4 





()()

************************************************************************************* 

 







I know that there are some great players in that basketball team, so most/all players in the team are great players. 



Each player of that basketball team is a great player, so the team is a g reat team.  

************************************************************************************* 

  







Most of the players in that team are great players. So Tim, being one of the few players in that team who do not come to daily training regularly, is also a great player.  



Since the team is a great team, Tim, being a player in the team, is also a great player. 

III5

False



Cause

 

 (a)  Post hoc Fallacy  

 B  A  B  A 

     



( b) The Fallacy of Slipper y Slope 

:

=/=



   _________________________________________

 



 

  | 

 

  

III6

The Fallacy of Denying Antecedent 

III7

The Fallacy of Affirming Consequent 

III8

Appeal to Ignorance  

    

: 



IV1 Complex Question  

 

 Have you stopped stealing? (  )

What do you admit if you answer this question? Yes 

No 

You admit you d i d  steal in the past.   You still engage in stealing now.  

  

IV2 Begging the Question / Circular Argument  /  

the conclusion

is stated or assumed as

one of  the

().

 Horse-riding is dangerous, because it is unsafe.

IV3 

False

Dilemma 

|/

   

premises.It is also known as circular argument