Reasoning and analytical thinking Keith Jones. Introduction l In this presentation we will: –Examine what critical thinking is; –Introduce the concepts

Reasoning and analytical Reasoning and analytical thinking thinking

Keith Jones

IntroductionIntroduction

In this presentation we will:– Examine what critical thinking is;– Introduce the concepts of reasoning– Introduce Analysis and analytical thinking

What is critical thinking?What is critical thinking?

“Active, persistent, and careful consideration of a belief or supposed form of knowledge in the light of the grounds which support it and the

further conclusions to which it tends.” (Dewey, 1909)

“an attitude of being disposed to consider in a thoughtful way the problems and subjects that come into the range of ones experiences…”

(Glaser 1941)

What is critical thinkingWhat is critical thinking

“Critical thinking is reasonable, reflective thinking that is focused on deciding what to

believe or do” (Norris & Ennis 1989)

“Critical thinking is that mode of thinking – about any subject, content or problem – in which the

thinker improves the quality of his or her thinking by skilfully taking charge of the

structures inherent in thinking and imposing intellectual standards upon them” ( Paul,

Fisher & Nosich, 1993)


Its an active process… you pursue it as a goal– Think for yourself– Raise questions yourself– Find information yourself

You do not rely on someone else (textbooks!!) In undertaking your critical thinking you should be

– Persistent and careful and not jump to conclusions– Look for the grounds that support a belief or position

» Reasons

– Be aware of the further conclusions to which it tends» Implications


Undertaking critical thinking is all about testing the validity of the reasons given by others to support the conclusions they have drawn. If the reasoning is at fault then the conclusions are probably at fault also.

Key skills for critical Key skills for critical thinkersthinkers Recognising problems Finding workable means to solve the problems Gather and organise relevant information Recognise un-stated assumptions To comprehend and use language with clarity

and accuracy To interpret data To appraise evidence and evaluate statements To recognise the existence of logical relationships To draw and test conclusions and generalisations

Interpreted from Glaser 1941.

Reasons and conclusionsReasons and conclusions

During your studies as a Masters student you will come across situations in which someone will be presenting you with a point of view and with the reasons why you should accept it– In lectures– In group discussions– In tutorials– In Crits– In textbooks– In other writing


You will also be expected to present arguments– Orally– Written– Drawings

How do you identify what reasoning is being presented by others?

How do you present reasoning yourselves?


Lets take a simple example“Many substantial environmental problems cannot be solved by individual or local action,

for example, the pollution caused by automobile exhaust gasses is a world-wide

problem, so such problems can only be addressed by international action” (Fisher,

2004) What is the conclusion?





2004) What is the conclusion ?





2004) What is the conclusion ? What are the reasons given to support the

conclusion?






conclusion?






conclusion?

How do you recognise How do you recognise reasons?reasons? There are several standard words and phrases

that people use to indicate that they are presenting conclusions and reasons.

Therefore, So, Hence, Thus, consequently, etc I conclude that…, It follows that… etc

– These are often referred to as conclusion-indicators Because, Since, For, etc The reasons are…, firstly, secondly etc…

– These are often refereed to as reason-indicators Unfortunately not everyone presents there

arguments using these words.

How do you recognise How do you recognise reasons?reasons?“We need to make rail travel more attractive to

travellers. There are so many cars on the road that the environment and human safety are under threat. Rail travel should be cheaper. Everyone wants the roads to be less crowded, but they still want the convenience of being

able to travel by road themselves. People will not abandon the car in favour of the train

without some new incentive” (Fisher 2004)

Hopefully you can recognise this as some form of argument.





The problem is that the reasons and conclusions have been mixed up and as such are not immediately clear.





To simplify things we are going to apply the ‘therefore’ test.





Can we apply a conclusion-indicator between sentences to make the passage clearer?

How do you recognise How do you recognise reasons?reasons?

“We need to make rail travel more attractive to travellers THEREFORE There are so many cars on the road that the environment and human safety are under threat. Rail travel should be cheaper. Everyone wants the roads to be less crowded, but they still want the convenience of being able to travel by road themselves. People

will not abandon the car in favour of the train without some new incentive” (Fisher 2004)

Can we apply a conclusion-indicator between sentences to make the passage clearer? No


“We need to make rail travel more attractive to travellers. There are so many cars on the road

that the environment and human safety are under threat. THEREFORE Rail travel should be cheaper. Everyone wants the roads to be less

crowded, but they still want the convenience of being able to travel by road themselves. People

will not abandon the car in favour of the train without some new incentive” (Fisher 2004)

Can we apply a conclusion-indicator between sentences to make the passage clearer? Yes – in part


“We need to make rail travel more attractive to travellers. There are so many cars on the road

that the environment and human safety are under threat. Rail travel should be cheaper THEREFORE Everyone wants the roads to be

less crowded, but they still want the convenience of being able to travel by road

themselves. People will not abandon the car in favour of the train without some new incentive”

(Fisher 2004)

Can we apply a conclusion-indicator between sentences to make the passage clearer? No





The whole analysis would have been much easier if the argument had been written….


“There are so many cars on the road that the environment and human safety are under

threat. Everyone wants the roads to be less crowded, but they still want the convenience of

being able to travel by road themselves. People will not abandon the car in favour of the train without some new incentive. We need to make rail travel more attractive to travellers.

Rail travel should be cheaper.” (Fisher 2004)

Where all the reasons precede the conclusions.


“There are so many cars on the road that the environment and human safety are under

threat AND Everyone wants the roads to be less crowded, but they still want the

convenience of being able to travel by road themselves AND People will not abandon the car in favour of the train without some new incentive THEREFORE We need to make rail

travel more attractive to travellers THEREFORE Rail travel should be cheaper.”

(Fisher 2004)

Patterns of reasoningPatterns of reasoning

Up to now I have presented you with very simple patterns of reasoning.– reason so conclusion– reason and reason so conclusion– reason and reason so conclusion so conclusion

There are more complex patterns of reasoning– reason (s) so conclusion but reason (s) therefore

conclusion


Much of genetic diversity in humans has evolved to protect us against the huge variety of pathogens

that prey on us…. This inevitably means that some of us are more susceptible than others to a

particular disease. But… genetic diversity can also protect this group. If the people who are likely to catch a particular disease are in a minority, then

each of them will be surrounded by others who are more resistant to the disorder. So many

susceptible people may never come into contact with the disease.

(New Scientist 23 March 1996, p. 41)


Much of genetic diversity in humans has evolved to protect us against the huge variety of pathogens

that prey on us…. This inevitably means that some of us are more susceptible than others to a

particular disease. But… genetic diversity can also protect this group. If the people who are likely to catch a particular disease are in a minority, then

each of them will be surrounded by others who are more resistant to the disorder. So many

susceptible people may never come into contact with the disease.

(New Scientist 23 March 1996, p. 41)


Much of genetic diversity in humans has evolved to protect us against the huge variety of

pathogens that prey on us…. This inevitably means that some of us are more susceptible

than others to a particular disease. If the people who are likely to catch a particular disease are

in a minority, then each of them will be surrounded by others who are more resistant to the disorder. So many susceptible people may never come into contact with the disease. Thus genetic diversity can also protect this group.

Disjunctions and Disjunctions and hypotheticalshypotheticals These are important because they complicate

the simply lines of reasoning that we have been investigating.

A disjunction is a sentence in which two or more options are presented as reasons or conclusions

“either the headmaster or the secretary stole the money”

You must never split a disjunction up.

Disjunctions and Disjunctions and hypotheticalshypotheticals A hypothetical is similar“If global warming is happening on a significant

scale, then the area of polar ice will show a steady decline over the long term”

The author is not presenting a reason and conclusion but is simply claiming a link between global warming and the size of the ice cap.

The key to identifying hypotheticals is the use of words like – If……Then.

Main patterns of reasoningMain patterns of reasoning

Before we move on to understanding and evaluating reasoning we need to briefly look at other patterns of reasoning that you may encounter.

So far all the examples that I have given you are based on deductive logic– If a = b AND b = c THEN A must equal c – A conclusion follows logically from a set of reasons. If

the reasons are true then the conclusion must be true.– All men are mortal. Socrates is a man. Therefore

Socrates is mortal However there are other types of reasoning that

you will come acrossRead Garnham & Oakhill, Thinking & Reasoning, Chapter 5.


Syllogistic reasoning is a more complex form of deductive reasoning.

In this form of reasoning you are presented with four sets of premises– All A are B– Some A are B– No A are B– Some A are not B

From these you deduce relationships


Example 1– All of the artists are beekeepers– All of the beekeepers are chemists– Therefore All the artists are chemists

Example 2– All of the beekeepers are artists– None of the chemists are beekeepers– What can we say about chemists and artists?– Some of the artists are not chemists.

All beekeepers are artists

No chemist are beekeepers

Some artists are not chemist

All artists are not chemist

Read Garnham & Oakhill, Thinking & Reasoning, Chapter 6.


Inductive reasoning is where the generalisations (conclusions) have been derived from observations (information).

The laws of science are based on an inductive line of reasoning.

Inductive reasoning often generates hypotheses which require testing or are based on statistical evidence which requires qualification.

We will look at these in the related Research Methods course.

Understanding reasoningUnderstanding reasoning

When someone presents an argument they often leave things unsaid which nonetheless they believe to be true and relevant to the argument.

These are known as assumptions. Identifying assumptions is important as they

can add or remove weight from the argument Identify assumptions is not always straight

forward– In essence they are other information that is needed

to support the argument


A teacher is speaking to a colleague about a student before an exam and says “Jones has worked hard so he will pass the exam”

The teacher has assumed (amongst other things) that– Jones is clever enough– That he has been well taught– That the exam is no more difficult than usual– That he doesn’t suffer from exam nerves– Etc

None of these are said but must be true if the conclusion is to be valid.


Context affects lines of reasoning– Personal context– Cultural context– Political context– Historic context

All of the above could affect the lines of reason, underlying assumptions and the conclusions drawn.

Putting it all together – so Putting it all together – so farfar A thinking map Analysis

– What is/are the main conclusions?– What are the reasons (data, evidence)?– What are the assumptions?– Clarify the meaning.

Evaluating reasonsEvaluating reasons

Are the reasons acceptable (true)– Your general knowledge of the subject

» More men are employed in the construction industry than women – would be true in the UK

– How certain is what is claimed?» What language is used – I observed is stronger than I

interpreted..

– Does the context affect the acceptability?» History etc

– Does it require expert knowledge to decide?» Beyond that of the reader

– Is it from a credible source?

Does the reasoning support Does the reasoning support the conclusions?the conclusions? When moving from reasons to conclusions we

have to draw inferences Inferences are the steps that move us from

reasons to conclusions So are those steps valid?

Does the reasoning support Does the reasoning support the conclusions?the conclusions?

“Women’s brains are smaller than men’s, therefore woman are less intelligent”

Even if the reason is true there is obviously something wrong with the conclusion.

What is wrong is the link (or inference) between the reason and conclusion.

You cannot make the move between the reason and the conclusion without further information (reasons)

The reason does not support the conclusion.

Evaluating inferencesEvaluating inferences

Are the inferences deductively valid (logical)? Are they proved beyond reasonable doubt? Is the balance of evidence in their favour? Do underlying assumptions affect the

inferences? Is the case well argued? What is your overall judgement of the

argument? Are there other arguments/considerations that

strengthen/weaken the case?

Evaluating argumentsEvaluating arguments

To summarise for an inference to be good we must be able to see the links between reasons and conclusions– Could the reasons be true and the conclusions be

false? Can you think of ANY way the reasons could be

true and the conclusion false? – deductively valid

If the reasons are true, is there a reasonable doubt about whether the conclusion is true? – balance of probability.

Putting it all togetherPutting it all together

A thinking map Analysis

– What is/are the main conclusions?– What are the reasons (data, evidence)?– What are the assumptions?– Clarify the meaning.

Evaluation– Are the reason acceptable and credible?– Does the reasoning support the conclusions?– Are there other arguments/considerations which

strengthen/weaken the case.

ConclusionConclusion

If you go through the process on the previous slide for each argument you are presented with then you will begin to think critically about the subject you are studying.

In the remainder of this course you will put some of the theory I have outlined into practice.

Documents

Reasoning and analytical thinking Keith Jones. Introduction l In this presentation we will: –Examine what critical thinking is; –Introduce the concepts