Informal Logic Fallacies B – focus on how the argument is structured and they way terms are used

Group B – Appeal to Ignorance

Two possible forms:

• There is no evidence for the truth of x, so x is false

• There is no evidence for the falsehood of x, so x is true

• Ignorance refers to the lack of evidence for something, which is used to leap to the conclusion that the opposite is true

• E.g. Unicorns exist because no one has proved that there are no unicorns

• However, if we claim that something exists, then we are required to provide evidence for its existence. Failure to do this leads to a reasonable conclusion that it probably does not exist

• Our justice system – innocent until proven guilty…

Group B – Circular Argument

• An argument cannot use inductive reasoning as evidence of truth – induction cannot be used to argue for induction

• David Hume - Inductive problem with induction

Group B – Circular Argument Example

• Eg Marcelo is good at communicating because he’s great at talking to people.

• Eg Dogs are called “man’s best friend” because they’re the friendliest animals.

• E.g. You need to do your homework because homework is required for this class.

Group B – Loaded Term

• This is when an argument uses a term broadly or narrowly to drive a conclusion

• E.g. Bangladesh needs economic support. It is a Third World country, so it is our moral responsibility to give financial aid to the people living there

• The term “Third World” is misleading and holds a negative connotation

• Originally used during Cold War (1st world –NATO/Capitalism, 2nd world – Soviet Union/Communism, 3rd World – not aligned with either, but were experiencing challenging economic times (no concrete criteria for designation)

Group B – Slippery Slope

• This occurs when an argument attacks an action/policy because the action would trigger a chain of events that are undesirable – To avoid result, avoid action (weak evidence that the chain of events will occur)

• E.g. How deep will the screening process become? Will airline passengers be required to get two professionals to vouch for them or endure intrusive personal questions about their sex lives in order to exercise the privilege of airline travel? And why stop at airlines? Buses and trains can become weapons of mass destruction, too. Then there are all those whizzing fuel bombs on our highways. From there it is only a short hop to, ‘Papers, please,’ while you are on your way to the store for a quart of milk. (The Toronto Star, September 2002)

Equivocation

• finding a false equivalent of something to make connections

• Usually happens when you find alternate meanings of the words

  • Eg. P53 idea of "nothing"

  • P. 53 idea of "nobody"

• P. 54: Which words are being used for an equivocation for the argument?