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If one were to reason that most poor people worry about money and most UBER-wealthy people don't worry about money, and they want to be UBER-wealthy, than they should simply not worry about money...

I feel like there are two types of processing going on here...

•That they think that 1 thing alone can lead to another
•That they are seeing an effect of a cause and thinking that they can work backwards starting with the effect and get to the cause.

I am interested in what you would call the latter of the two issues I pointed out above... What is this type of faulty reasoning called?

Thankyou, God bless!

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1 Answer 1

up vote 3 down vote accepted

If they are wealthy then they don't worry about money
they don't worry about money
Then they are wealthy.

This is "affirming the consequent" fallacy.
1) If P, then Q.
2) Q.
3) Therefore, P.

An argument of this form is invalid, the conclusion can be false even when statements 1 and 2 are true. Since P was never asserted as the only sufficient condition for Q, other factors could account for Q. To put it differently, if P implies Q, the only inference that can be made is non-Q implies non-P.

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"affirming the consequent" Thankyou very much! :) –  Albert Renshaw Feb 26 '13 at 23:27
@AlbertRenshaw It is sometimes called "modus morons". –  Dennis Feb 27 '13 at 2:22
Very nice @Dennis Thankyou very much! +1 –  Albert Renshaw Feb 27 '13 at 3:31

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