Beliefs & fallacies
Stephen's guide
Books & software
• General
• Legal
• READER'S
• HARVARD
| < Previous | | Next > |
- Each of these fallacies is characterized by an illegitimate use of some logical operator (or, not, if-then, and) to distract the reader from the apparent falsity of a certain proposition. The following fallacies are fallacies of distraction:
- False Dilemma: misuse of the "or" operator
- Argument From Ignorance: misuse of the "not" operator
- Slippery Slope: misuse of the "if-then" operator
- Complex Question: misuse of the "and" operator
- 1. False Dilemma:
- A limited number of options (usually two) is given when actually other choices are available. A false dilemma is an illegitimate use of the "or" operator. Putting issues or opinions into "black or white" terms is a common instance of this fallacy.
Examples:
- Either you're for me or against me.
- America: Love it or leave it!
- Either support Meech Lake, or Quebec will separate!
- Every person is either wholly good or wholly evil.
Convincing Others: Identify the options given, and show (with an example) that there is an additional option.
Reference: Cedarblom and Paulsen: 136
- 2. Argument from Ignorance (argumentum ad ignorantiam):
- Arguments of this form assume that since something has not been proven false, it is therefore true. Conversely, such an argument may assume that since something has not been proven true, it is therefore false. (This is a special case of the false dilemma above, since it assumes that all propositions must be either (a) known truths or (b) known falsehoods.) As Davis writes, "Lack of proof is not proof" (p. 59).
Examples:
- Since you cannot prove that ghosts do not exist, they must exist.
- Since scientists cannot prove that global warming will occur, it probably won't.
- Fred said that he is smarter than Jill, but he didn't prove it. So it must be false.
Convincing Others: Identify the proposition in question. Argue that it may be true even though we don't know whether it is or isn't.
References: Copi and Cohen: 93; Davis: 59
- 3. Slippery Slope:
- To show that a proposition, P, is unacceptable, a sequence of increasingly unacceptable events are argued to follow from P. A slippery slope is an illegitimate use of the "if-then" operator.
Examples:
- If we pass laws against fully-automatic weapons, it won't be long before we pass laws on all weapons. Then we will begin to restrict other rights and end up living in a communist state. Thus, we should not ban fully-automatic weapons.
- You should never gamble. Once you start gambling you will find it hard to stop. Soon you will spend all your money on gambling, and eventually you will turn to crime to support your earnings.
- If I make an exception for you, I'll then have to make an exception for everyone!
Convincing Others: Identify the proposition P being refuted and identify the final event assumed as a consequence. Then show that this final event is either an irrational or unnecessary consequence of P.
Reference: Cedarblom and Paulsen: 137
- 4. Complex Question:
- Two otherwise unrelated points are conjoined and treated as a single proposition. The reader is expected to accept or reject both together, when in reality one is acceptable while the other is not. A complex question is an illegitimate use of the "and" operator.
Examples:
- You should support home education and the God-given right of parents to raise their children according to their own beliefs.
- Do you support freedom and the right to bear arms?
- Have you stopped using illegal sales practices? (This asks two questions: “Did you use illegal practices?” and “Did you stop?”)
Convincing Others: Identify the two propositions illegitimately conjoined and show that believing one does not necessarily implicate belief in the other.
References: Cedarblom and Paulsen: 86; Copi and Cohen: 96
Reprinted with permission from Professor Stephen Downes.
All opinions expressed in this web site, unless otherwise noted, are my own, Michael Gaspard. If you notice any errors or have any suggestions for improvement, please let me know by e-mailing webmaster@mdpme.com. Thank you!This web page was last updated on Thursday, April 29, 2004.
http://www.mdpme.com/fallacy3.htm