[Study] Critical Thinking Skills - Fallacies

All of these understandings were taken from:

Critical Thinking Skills - Developing Effective Analysis and Argument
by Stella Cottrell
2nd edition

A. Initial understanding:

Author's position:

Is the underlying point of view that the presenter/author aims to convey to their audience.

It is important to make the author's position clear in the introduction

Assumptions: 

Example: Holidays are a time for relaxation and enjoyment. This year, thousands of people will have their holidays ruined by oil spills along our beaches.

• Assumption 1: holidays are for relaxation?
• Assumption 2: thousands of holiday-markers will want to go to the beach?
• Assumption 3: holiday-markers will not like oil?
• Assumption 4: oil can ruin a holiday?
• Assumption 5: audience can understand words like holiday, beach, relaxation, enjoyment, ruined, our, and oil spill? no need for definitions?

Flaws:

• Confusing cause and effect
• Failing to meet necessary conditions
• Attacking the character of a person rather than evaluating their reasoning
• Misrepresentation
• Using emotive language

Primary source vs Secondary source

Example: Magazine articles written in the 1950s were secondary sources when published, but a primary sources for present-day research into life in the 1950s.

• Primary source materials are those that originate from the time and place of the events being investigated.
• Secondary source materials are those that are written or produced about the event, usually some time later.

B. Fallacy categories:

1. False premises (p.91)

"A leads to B"

"When A is an incorrect assumption" then the Argument is based, or predicated on false premises.

Example: Getting wet in the rain gives you a cold. The builders worked for several hours in pouring rain. Therefore, they will get colds.

• False premise: getting wet in the rain gives you a cold

2. Two wrongs don't make a right (p.120)

"A leads to B"

"A did so and A are similar to B therefore B can" then the Argument can be a flawed argument.

Example: If one person cheats in an exam, then it is not reasonable to argue that other people should be able to cheat too.

• Two wrongs don't make a right: A cheated does not mean B can reasonably cheat too.

3. Stereotyping (p.96)

B is an association of group A (adjectives, job roles, or form of behaviour)

"An idea or a set of A are continually linked to B" then this assumption reinforces the stereotype.

Example: On the left, we have the man's bathrooms, no doubt for the doctors, and over there are the ladies' bathrooms for the nurses.

• Stereotype:  This reinforces the stereotype that Doctors are men and Nurses are women.

4. Lack of consistency in the argument (p.65,67)

Internal consistency:

• Clarity and internal consistency
• all parts of the line of reasoning contribute to the conclusion (clear authorial position)
• nothing then contradicts or undermines the main message
• Example: Apples are good for your teeth. Acid corrodes. Apples consist mainly of acid so they can't be good for teeth. => left wondering whether apples are good for teeth or not. => lacks internal consistency.

• Including opposing arguments
• strong line of reasoning will usually give consideration to alternative points of view
• Make the authorial position clear throughout the line of reasoning
• Introduce an alternative point of view
• Counter arguments to show alternative view is less convincing
• Resolving any apparent contradictions by showing how the main argument holds true.

Logical consistency:

Check whether the reasons given by the author do indeed support the conclusion (authorial position). (checking for logical consistency).

Example: There was a murder near the station last night. There are always young lads hanging around there. One of them probably did it. He local council should ban young people from hanging around the station.

There is nothing to show that:

• These young people did commit the murder;
• Even if they did so, other young people would do the same;
• A general ban on young people would prevent future murders.

5. Unnecessary background information (p.58)

Arguments are not provided separately for other material. They may be surrounded by:

• Introductions
• Descriptions
• Explanations
• Background information
• Summaries
• Other extraneous materials => to be avoid.

6. Lack of precision (p.65)

Imprecise wording is a common cause of inconsistency

Example: He author's opening statement is that 'Apples are good for your teeth.' However, by the end of the passage, the author is arguing that the acid is 'relatively harmless' and that 'apples are more beneficial than alternative snacks' => relative benefits is not the same as the absolute statement that 'apples are good' (authorial position).=> lacks internal consistency

7. Assumption that is not supported by the evidence (p.88-89)

'Non-sequitur' means 'doesn't follow on'. Sometimes, we can guess that there must be a hidden assumption because the conclusion seems to jump out of nowhere, rather than following on from the sequence of reasons.

Example: The number of people in prisons continues to rise each year and is much higher than it was over a hundred years ago. Many prisons are now overcrowded. Rehabilitation of criminals would be a much better option. => doesn't follow on

8. Incorrectly assuming a causal link (p.106)

A and B are found together or occur at the same time

It is flawed reasoning to assume that there must be a link between them.

Example: Wherever dinosaur imprints are found in rocks, there are geologists around. Therefore, geologists must make the imprints.

• Geologists and Dinosaur prints occur in the same place. It is flawed reasoning to assume that geologists fake the prints.

9. False correlation (107)

A correlation assumes some kind of mutual relationship.

A and B having trends move in the same direction, this does not mean there is a correlation between them, as there may be no relationship. If a correlation is assumed whether none exists, this is a false correlation. It is also a flawed reasoning.

Example: The number of car crimes has increased. There used to by only a few colours of car from which purchasers could choose. Now there is much more variety. The wider the choice of car colours the higher the rate of car crime.

• The connection between 2 trends is likely to be coincidental rather than correlated.

10. Meeting necessary and sufficient conditions (p.109-110)

A leads to B (A is a condition of B)

If A is not existed, occurs, then there is no B => Necessary condition

If only A can prove B => Sufficient condition

Example: One way of marking a lot of money is by winning the lottery. In other to win the lottery, you have to have a lottery ticket for the draw. John has a lottery ticket for the draw so he will make a lot of money.

• Ticket is a necessary condition that John met.
• However it is not sufficient to make money because the ticket might not win.

11. Over-generalisation (139)

Generalisations are useful as they help us to see patterns and to make judgements more quickly when this is needed. However, a generalisation should be well-founded, based on a reasonable sample.

An over-generalisation is one based on too small a sample to justify the generalisation. 

Example: My first child slept through the night but the second one was a very poor sleeper. First-born children are better at getting to sleep than their younger brothers and sisters.

• This is a database of two, which is a very small sample. If thousands of other first-born and second-born children showed the same sleeping pattern, then the generalisation might be valid.

12. False analogy (p.112)

A is compared to B due to some similarities between two things.

If the comparison helps to give a more accurate understanding, then it is likely to be valid.

An false analogy is (It is also a flawed reasoning)

• A and B are not sufficiently similar, or
• the comparison is misleading, or
• A used for comparison is described inaccurately.

Example: There was no way the defendant was able to help himself. He had been under excessive strain for some time and his emotions had been building up like steam under pressure. The witness had been goading the defendant, knowing he was likely to get angry. The defendant was like a pressure cooker, just waiting to explode. Eventually, he just reached boiling point and an explosion became inevitable.

• This compares emotions to a pressure cooker. This comparison made in order to argue that emotions cannot be controlled. However, the comparison isn't valid as it isn't comparing like with like: human emotions are not like steam under pressure. The underlying argument is based on false premises: that emotions cannot be controlled and that pressure cookers inevitably explode at boiling point. The comparison does not hep us to understand why the defendant couldn't control his emotions.

13. Deflection (p.114)

An author can use language to suggest there is no need to prove the argument, deflecting the audience from critically evaluating the reasoning. (It is also a flawed reasoning)

• Words: obviously, of course, clearly, naturally
• Appeals to modern thinking: we're not in the 19th now, it's no longer 1940, it;s like being back in the ark!

14. Complicity (p.114) (in group)

A particular form of deflective language where the author acts as if the reader were already part of a group of like-minded thinkers.

Example:

• Everybody knows: as we all know, surely, we all share the view that ...
• People like us: Anyone with any sense knows that women are naturally better at housework than man.

15. Exclusion (p.114) (out-group)

The in-group tends to make the out-group appear inferior and undesirable so that others want to avoid being associated with them. Authors can present opponents of their argument as an 'out-group'.

Example:

• A decent people would agree that...
• As British people, we all want...

16. Unwarranted leaps (e.g. castle of cards; sleight of hand) (p.116)

Where there are unwarranted leaps, the author appears to add two and two to make five. The argument races ahead, leaving gaps in the reasoning, and relying on unsubstantiated assumptions.

• Castle of cards: the argument relies on a set of interconnected reasons and assumptions and is very delicately balanced. If one reason or assumption is proved incorrect, the argument collapses easily.
• Sleight of hand: is a 'cunning trick' that can go unnoticed. Example: the author jumps from a line of reasoning that appears to be discussing tolls, to a conclusion that argues for heavy tolls.

17. Emotive language (p.117)

Emotive language uses words, phrases and examples that intend to provoke an emotional response. Some subjects such as children, parents, national pride, religion, crime and security are emotive. Using these unnecessarily as arguments can manipulate the audience's emotions. (It is also a flawed reasoning)

18. Attacking the person (p.117)

Attacks on the person rather than the argument are often used to undermine the credibility of an opposing point of view - but it is not a valid method of critical reasoning. (It is also a flawed reasoning)

The exception is where there is a valid reason for showing that the opponents either have a history of being dishonest or have not revealed their vested interests in the debate. 

19. Misrepresentation (p.119) [straw man]

One way of distorting an argument is by presenting the options or opposing arguments in an unfair or unbalanced way. (It is also a flawed reasoning)

• Ignoring the main opposing reasons: by focusing on its minor points and ignoring its chief supporting reasons. 
• Presenting restricted options: present an argument in such a way that it looks as if there are only two possible conclusions or options for action
• Misrepresenting a person: focusing on certain characteristics of a person, especially those irrelevant to the main argument.

20. Trivialisation (p.119)

Example: Many of us had intensive training on an instrument such as the piano when we were children, but we obviously did not all turn out to be a Beethoven or Mozart.

The argument is trivialised by focusing on relatively rare cases of 'genius' rather than on how intelligence operates for most people. Besides, by references to potentially common experiences such as childhood piano lessons, These further trivialise the subject. (It is also a flawed reasoning)

21. Tautology (p.120)

A line of reasoning should take an arguments forward. Tautological arguments, on the other hand, merely repeat the same points in different words, without advancing the argument.

Example: More people should be informed of the value of studying maths to a higher level at school or university. A mathematical education can be very advantageous. Therefore, the guidance given to young people should emphasise the benefits of choosing maths.