An argument which is intended to prove one thing instead proves a different conclusion altogether.
- Crimes of theft and robbery have been increasing at an alarming rate. The conclusion is obvious: we must reinstate the death penalty immediately.
(We may agree with the premise but rather infer that we should initiate programs to eliminate the causes of theft and robbery. This example from Hurley, 126).
- You should support the new housing bill. We can't continue to see people living in the streets; we must have cheaper housing.
(We may agree that housing is important -- even though we disagree with the housing bill.)
- I say we should support affirmative action. White males have run the country for 500 years. They run most of government and industry today. You can't deny that this sort of discrimination is intolerable.
(The author has proven that there is discrimination, but not that affirmative action will end that discrimination.)
Proof: Show that the conclusion proved by the author is not the conclusion that the author set out to prove. Identify the correct conclusion entailed by the premises.
Copi and Cohen: 105; Hurley 125-6.