Logical Fallacies and Science In The Media

Question 1

What is a fallacy?

2

Answer 1

A fallacy is an error in reasoning

Common errors that undermine the logic of your argument

Question 2

What are logical fallacies?

3

Answer 2

Logical fallacies are defects in arguments

They can be subtle and easy to miss

Arguments can be superficially convincing but ultimately weak because of one of these flaws

Question 3

List some of the main fallacies.

8

Answer 3

Non Sequitur (Does Not Follow)

False Analogy

Slippery Slope

False Cause (Post Hoc ergo propter hoc)

Circular reasoning

Argument to the person (ad hominem)

Appeal to authority

Argument from Personal Incredulity

Question 4

What is meant by non sequiter (does not follow)?

Answer 4

A conclusion that does not follow logically from preceding statements or that is based on irrelevant data

Question 5

Give an example of a non sequiter statement.

1/4

Answer 5

Mary loves children, so will make an excellent schoolteacher.

Jenny drives a Mercedes. Jenny must be wealthy.

His apartment building is huge. His apartment must also be huge.

Billy is eating broccoli. Billy must love to eat vegetables

Question 6

Give two scientific examples of non sequiter statements.

Answer 6

John successfully carried out a tissue stain in the laboratory therefore John should receive the Nobel prize

This drug successfully lowers blood pressure, therefore this drug must kill cancer cells

Question 7

What is false analogy?

Answer 7

The assumption that because two things are alike in

some respects, they are alike in others

Question 8

Examples of false analogy.

2

Answer 8

Phones and bananas fit into the hand, therefore phones should be edible

Heroin and cannabis are both drugs. Heroin can be lethal, therefore cannabis should be illegal

Question 9

Give an example of a scientific false analogy

Answer 9

If antibiotics treat bacterial infections, they should also treat viral infections

Question 10

What is a slippery slope fallacy?

Answer 10

Asserting that if we allow A to happen, then Z will

consequently happen too, therefore A should not happen

Question 11

Give some examples of slippery slope fallacies.

Answer 11

If we allow abortion, soon it will be legal to kill children

If we legalise drugs, everyone will become a drug addict

Legalizing divorce is undesirable because it would cause more families to break up, which would finally result in the destruction of civilisation

Question 12

Give an scientific example of a slippery slope fallacy.

Answer 12

Genetic modifications of embryos will lead to designer

babies and eugenics and so should not be allowed

Question 13

What is False Cause (Post Hoc ergo propter hoc)?

Answer 13

The assumption that because two events occur together, or in sequence, one must cause the other

Question 14

Give some examples of false cause fallacy.

3

Answer 14

Before women got the vote, there were no nuclear weapons. Therefore, women voting caused the development of nuclear weapons

Roosters crow just before the sun rises. Therefore, rooster crowing causes the sun to rise

Most couples that divorce see a therapist before the separate. Therefore, therapists cause divorce

Question 15

What is correlation?

Answer 15

Association between variables

Question 16

What is causation?

Answer 16

One variable causes the other

Question 17

Give a scientific example of false cause fallacy.

Answer 17

A child develops autism shortly after getting the MMR

vaccine, therefore the MMR vaccine causes autism

Question 18

What is circular reasoning?

Answer 18

A is true because B is true; B is true because A is true

Question 19

Give an example of circular reasoning.

Answer 19

The Bible tells us that it is the word of God
The word of God is infallible
Therefore the Bible is infallible

Question 20

What is argument to the person (ad hominem)?

Answer 20

An attack on the person proposing an argument rather than on the argument itself.

Question 21

Give an example of argument to the person (ad hominem) fallacy.
(2)

Answer 21

There are stories that Prof. O’Brien is an adulterer, therefore his research is not worth considering.

Prof O’Brien’s research says drinking alcohol is bad for you, but he drinks alcohol, therefore his research is not valid.

Question 22

What is Appeal to Authority?

3

Answer 22

Person A is (claimed to be) an authority on a subject .

Person A makes claim about that subject.

Therefore, the claim is true.

Question 23

Give an example of appeal to authority fallacy.

2

Answer 23

“Prof. O’Neill is a respiratory physician that doesn’t believe smoking causes cancer.

Therefore, smoking doesn’t cause cancer”

Question 24

What is Argument from Personal Incredulity?

Answer 24

I cannot explain or understand this, therefore it cannot be true

Question 25

Give an example of an argument from personal incredulity.

2

Answer 25

The creationist (“intelligent design”) argument
- there are features of the natural world that we cannot explain. This is taken as evidence that God designed all creatures as they exist today and evolution is incorrect

“I can’t believe that something as intricate as an eye could come about by random mutation”