1. Cost of Fallacious Reasoning
Sujal Upadhyay
BIM 7th Semester
Critical Thinking and Decision Making
2. Fallacy
• It is a type of argument that seems
to be correct but on verifying it may
not be correct.
3. Types of Fallacy
Fallacies of Relevence:
• Arguments are irrelevent to conclusion
• If he fails in exam then he says that his father was
ill
Fallacies of Defect Induction:
• The connection between arguments and
conclusion is not strong enough to support the
conclusion
• He met two americans, both were white and says
all americans are white
4. Fallacies of Presumption
• Too much is asumed in the premises
• If someone takes some photographs then he is
a photographer
Fallacies of Ambiguity
• Ambigious word or phrase has multiple
meanings in different situations
• Using these phares in arguments does not
support the conclusion
• Ram is a boy and all boys can run fast then
Ram can also run fast
5. Common Problems of Critical
Thinking
Association effect:
• If two events occur at the same time, our
mind will form association between them.
• If it is heard that a sumo crashed this morning
and Ram was travelling in sumo the same
morning then we may think ram was in the car
crash.
6. Incomplete Comparisions:
• Comparisions are made without providing the
other half of camparision.
• In a group of students, if it is said that Ram is tall
and he can run fast then taller than who? Faster
than who? Is not mentioned.
Weak Analogies:
• Two events or objects are analogous when ther
share common properties.
• If Shyam can play football then Ram also can
because they are brothers.
7. Part-Whole:
• Whatever is true of the whole, is also true of
all its parts and vice versa.
• If it is said that students of BIM are intelligent
then some of them may not be so.
Irrelevent Reasons:
• Reasons or arguments are not related to
conclusion.
• All students should take foreign classes, it will
help to improve quality of education.
