Fallacy

genetic fallacy

• argues against the truth of a claim on the basis of its origin

• attacks the source of the argument

ex.

Study showing that animals are mistreated on factory farms must be false, because it was funded and produced by an animal rights organization

fallacy of composition

• what is true of the parts must be true of the whole thing

ex

Since an individual brick is not visible from a mile away, it follows that a building made of bricks, no matter how tall, will not be visible from a mile away

Fallacy of Division

• arguing that what is true of the whole must be true of the parts

ex

The cake is sweet so all of its ingredients must be sweet

Ad hominem Abusive

• rejecting a claim by criticizing the person who makes it rather than the claim itself

• calls names to discredit position

ex.

His criticism of the government’s welfare policy must be wrong, since he is a known racist

Ad hominem tu quoque

• rejecting a claim by accusing the person who makes it of hypocrisy

• they don’t follow their advice so they must be wrong

ex

we can reject his assertion that Americans have a moral duty to pay their taxes, since he often fails to pay all of his own taxes

Ad hominem Circumstantial

• rejecting a claim by pointing out that, given a person’s circumstances that person would be expected to make that claim

• criticize position because person making it is biased, person benefits from the conclusion

ex.

Of course she thinks the government should increase funding for welfare benefits, since she is a current recipient of such benefits. Clearly, her position is biased and therefore false

Fallacy of equivocation

• using the same word twice but changing the context meaning

ex.

I can read French, and since my neighbor is French, it follows that I can read him like a book

Appeal to popularity

• idea must be true because it is widely believed

ex.

Thousands of Americans support a strong war on crime, so it is right for the police to take very strong measures to stop crim

Appeal to tradition

• claim must be true because it is part of a tradition

ex.

Women have traditionally been accorded fewer educational opportunities than men, so it is right that men should be favored when it comes to spending on education in this country

Appeal to ignorance

• lack of evidence proves something

• claim has not been proven does not mean this it is false

• claim has not been disproven does not show that it is true

ex.

Since no one has proven that Bigfoot does not exist anywhere in the US, we should conclude that Bigfoot probably does exist

Appeal to emotion

• using emotions rather than evidence to persuade

ex.

As a proud American, you will surely be willing to give generously to help with our charitable campaign for poor disabled veterans

Red herring

• using irrelevant information as part of an argument

• used to distract opponents

ex.

Abortion can not be immoral; I know lots of women who have has an abortion

Straw Man

• discrediting someone’s position so it can be more easily attacked

ex.

We must reject the conservative proposal to reduce the size of government, because it would be dangerous to have a country without financial means to enforce the laws

Begging the question

• assuming the conclusion in a premise

ex.

Capital punishment is immoral because it is wrong for the state to take the life of a prisoner who is safely locked in prison

False dilemma

• when you say there are only two choices when there is actually more than that

ex.

Either we attack Iran, or we sit back and do nothing. But since doing nothing would allow Iran to get dangerous nuclear weapons, we must obviously attack that country with nuclear weapons

Slippery Slope

• no proof that all the ideas will lead to one another

ex.

If start drinking health shakes, then inspired to start running, then compete in marathon which will take hours of training, take time away from each other, causing marriage to suffer, therefore you drink health shakes then marriage will suffer

Hasty generalization

• sample is to small to make generalization

ex.

Both of the students who visited me during office hours are confused by the class material. I have to conclude that everyone in the class is confused

Faulty analogy

• try to compare two things that aren’t similar in relevant ways

ex.

My baby and my necktie are both things that belong to me. When I no longer like my tie, I get rid of it. Therefore, when I no longer care for my baby, I have the right to get rid of it