logical fallacies Rolofson 3

A key to his EMPIRE OF EVIL

Question-begging definition:

This fallacy consists in attempting

to establish an irrefutable position in an argument by means of

a questionable definition.

Question-Begging Definition

ex - When a popular politician switched from the

Democratic Party to the Republican Party several months ago, a

number of his critics, especially Democrats, claimed that he had

obviously not been a “true-blue” Democrat or he wouldn’t have

switched political parties.

Question-Begging Definition

ex- Person 1: A Christian would never drink alcoholic beverages.

 Person 2: That’s just not true. I know several Christians who occasionally

take a drink. In fact, I know a minister who does.

 Person 1: Then as far as I’m concerned, they couldn’t be real Christians.

Causal Oversimplification

This fallacy consists of

oversimplifying the relevant causal antecedents of an event or

series of events.

Causal Oversimplification

ex - “Children spend an average of six hours per day on

the phone or computer – time that used to be spent reading.

That explains why SAT scores are dropping.”

Post Hoc Fallacy

ex - “My soccer team was losing until I bought new

shoes.”

Post Hoc Fallacy

This fallacy consists in assuming that a

particular event, B, is caused by another event, A, simply

because B follows A in time. This fallacy is the faulty assumption

that because one event or action follows another, the first

causes the second.

Confusion of Cause and Effect

This fallacy consists of confusing

the cause with the effect of an event or in failing to recognize

that there may be a reciprocal causal relation between the two

events in question.

Confusion of Cause and Effect

ex - “It’s no wonder that Phillip makes such good grades

and always does what the teacher asks. He’s the teacher’s pet.”

Domino Fallacy

This fallacy – also known as the slippery slope

fallacy – consists of assuming, without appropriate evidence,

that a particular action or event is just one, usually the first, in a

series of steps that will lead inevitably to some specific

consequence.

Domino fallacy

exe - During the Vietnam War, it was widely argued that “if

we let the Communists have Vietnam, they will then take

Cambodia, Thailand, then all of Southeast Asia, and before you

know it, we will be in a Third World War.”

Gambler’s Fallacy

This fallacy consists of arguing that, because

a chance event has had a certain run in the past, the probability

of its occurrence in the future is significantly altered.

Gambler’s Fallacy

exe - “It’s been heads five times in a row. I’m sticking with

tails.”

Apriorism

This fallacy consists in refusing to look at any

evidence that might count against one’s claim or assumption.

An extension of this fallacy consists in being unwilling or unable

to specify any conceivable evidence that might possibly count

against one’s claim.

Apriorism

exe - “I couldn’t care less what is in your biology textbook. I

know that I didn’t come from some monkey or lower form of life

or whatever you call it.”

Leading Question

This fallacy consists of “planting” a proposed

answer to a question at issue by the manner in which the

question is asked.

Leading Question

exe - “You did plan to return the money that you borrowed

from the cash drawer, did you not?” In this case the defense

lawyer is “leading” the witness, by assuming a position on the

very question at issue – namely, whether the defendant

embezzled the money or whether he inappropriately

“borrowed” it. (Planting a proposed answer is not only likely to

be disallowed by the judge, it is also a procedure that is likely to

weaken the case for the defense).

Loaded or Complex Question

This fallacy consists in

formulating a question in a way that presupposes that a definite

answer has already been given to some other, unasked

question.

Loaded or Complex Question

exe - “Where will you be going to college next year?”

Loaded or Complex Question

exe - One of Senator Fisher’s constituents asks: “ Are

you going to vote for the proposed cut in the defense budget – a

cut that will surely weaken our military posture around the

world?”

Circular Reasoning

Arguing for a conclusion on the basis of a

set of premises, where the truth of the premises assumes the

truth of the conclusion.

Circular Reasoning

exe - “My cult leader is infallible; he tells me so, I know

what he tells me is true, because he’s infallible.”

Circular Reasoning

exe -

 CLAIM: “You can’t give me a C in this course…

 REASON: …because I’m an A student!”

 WARRANT: An A student is someone who can’t receive a C.