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Charlotte Vardy. Deconstruction of Arguments AKA Critical Thinking… Day 2 (9.15am – 12.00pm). The Critical Path: Deconstruction. The elements of an argument…. What is an argument?.

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Charlotte Vardy

Deconstruction of Arguments AKA Critical Thinking…

Day 2 (9.15am – 12.00pm)

The Critical Path:Deconstruction

The elements of an argument…

What is an argument?

An argument, in Critical Thinking, is not just a conversation in which two people hurl abuse at each other. Neither is it the same thing as straightforward disagreement.

There’s a difference between arguing with someone and merely contradicting them.

As Monty Python’s Argument Clinic sketch puts it, an argument is “a collected series of statements to establish a definite proposition”, an attempt to persuade by offering reasons.

The elements of an Argument

Any statement that attempts to persuade you that something is true by offering at least one reason for thinking that it is so counts as an argument.

The main elements of Arguments are reasons and a conclusion.

The ability to read a passage and pick out its conclusion and the reasons offered in support of it is perhaps the most basic skill required for Critical Thinking.

As you progress to more complicated arguments, you’ll also need to be able to spot intermediate conclusions


  • The reasons (premises) in an argument are the claims made in an attempt to persuade you that the conclusion is true.

  • A test that can help you to identify the reasons in a passage is the ‘because test’. Simply insert the word “because” into the passage directly before the phrase that you think is a reason. If the passage makes sense, then you’ve probably got the right section. If it doesn’t, then you haven’t.


  • When identifying the reasons in a passage in a written answer, you should give direct quotations.

  • If you give a rough paraphrase, then you risk changing the claim, resulting in inaccuracy in your answer and so opening yourself to criticism.


The conclusion of an argument is the main point that it is trying to get you to accept. You’ll often (but not always) find this statement either at the beginning or the end of a passage. It may be indicated by a word such as “therefore”, “thus”, or even “in conclusion”.

A test that can help you to identify the conclusion of a passage is the ‘therefore test’. Simply insert the word “therefore” into the passage directly before the phrase that you think is the conclusion. If the passage makes sense, then you’ve probably got the right section. If it doesn’t, then you haven’t.


  • When identifying the conclusion of a passage, you should give a direct quotation. If you give a rough paraphrase, then you risk changing the meaning of the phrase slightly, and so giving an inaccurate statement of the conclusion. This can leave you open to criticism. Even missing out a word or two can change the meaning of the conclusion resulting in inaccuracy in your answer. To err on the side of caution, always quote word-for-word.

Indicator words…

There are certain words that often indicate the presence of a particular element of an argument.

Conclusions are often indicated by one of the following words or phrases: “therefore”; “thus”; “hence”; “so”; “in conclusion”; “consequently”; “showing that”; “demonstrating that”; “proving that”; “establishing that”; “meaning that”; “entails that”; “implies that”; “as a result”. “Should”, “must”, and “ought to” may also be treated as indicator words, albeit cautiously.

Indicator words for reasons include the following: “because”; “as”; “since”; “in order to”; “otherwise”. Sometimes authors enumerate their reasons, writing “First, …”, “Second, …”, “Third, …” etc., which can also help in their identification.


Parents should control how children use mobile phones. (CONCLUSION)

Firstly, in many cases children use the devices during the night, causing them to lose sleep and be distracted from study. (REASON 1)

Secondly, since children tend to use phones more frequently than adults (with studies showing that they may send up to 80 SMS messages per day) there are often significant cost implications. (REASON 2)

Finally, the health risks associated with prolonged usage are still unknown, particularly in relation to developing bodies. (REASON 3)

Parents should control how children use mobile phones. Firstly, in many cases children use the devices during the night, causing them to lose sleep and be distracted from study. Secondly, children tend to use phones more frequently than adults, with studies showing that they may send up to 80 SMS messages per day. This has significant cost implications. Finally, the health risks associated with prolonged usage are still unknown, particularly in relation to developing bodies.

Intermediate Conclusions

  • An intermediate conclusion is something in an argument that functions both as a reason and as a conclusion. To function as a reason, it must offer support to the main conclusion of the argument (or to another intermediate conclusion). To function as a conclusion, there must be something else in the argument that lends it support.

  • “Your face is covered in chocolate, so it must have been you that ate my cake, so you owe me a cake.” The main conclusion of this argument is the final clause: “You owe me a cake.” This is supported by the previous clause, which is therefore functioning as a reason, “it must have been you that ate my cake.” This clause, though, is also supported by the previous clause, “Your face is covered in chocolate”, so it is both a conclusion and a reason; it is an intermediate conclusion.


An assumption is an unstated reason. It is something that must be true for an argument to work, but which is not explicitly stated in the argument.

For example, the argument “The college address is the same street as I’m standing on; therefore, the college must be nearby” assumes that the street isn’t very long. If the street is long, then the college could be on it but still miles away.


A counter-argument is an argument that goes against the author’s main conclusion. Typically, counter-arguments are considered and rejected in an attempt to strengthen the author’s case.

For example, “If Superman and Spiderman had a fight, then Superman would win as his ability to fly would mean he could attack from any angle. You might think that Spiderman’s ability to hurl webs (a ranged weapon) would give him the edge, but Superman would be manoeuvrable enough to dodge them.”

Group Work (1)

In groups of 3, read the article on Bob Geldof and try to identify the arguments within it…

Look for…

Conclusions and Intermediate Conclusions

Reasons (Premises)



Briefly weigh up the arguments made, considering their strengths and weaknesses and how you might respond to the article.

Types of Argument

Deductive or Inductive?

Deductive Arguments

  • Deductive arguments rely on their pattern and the logical relationship between the terms alone; if the premises are true the conclusion could not be false – it is NECESSARILY TRUE and constitutes formally strong evidence.

  • An example of a deductive argument is “A bachelor is an unmarried man: Peter is an unmarried man and therefore he must be a bachelor”, another example is “a=2 and b=3, therefore a+b=5.”

  • A deductive argument with the right form is considered to be valid, regardless of the truth of the premises. When the premises are in fact true and the argument is valid, then we call it sound.

Inductive Arguments

  • All other arguments are considered to be inductive –

  • Inductive arguments work because of the actual information in the premises: if the premises are true the conclusion is not likely to be false.

  • An example of an inductive argument could be “all the swans surveyed in Europe between 1650 and 1700 were white, therefore it is probable that all swans are white.”

  • It is always possible that an inductive argument is wrong (the evidence may always be incomplete or misleading) and therefore it provides only formally weak evidence

  • Confusingly, Inductive arguments are sometimes described as strong (the conclusion is more likely to be true because of support provided by the premises) or as weak. When an inductively strong argument does have true premises, we call it cogent.

Key Point

  • The difference is between deductive and inductive arguments is really between certainty (we can be sure the conclusion is correct) and probability (we can bet on the conclusion being correct).

  • It is worth noting that deductive arguments don’t typically tell us very much – but inductive arguments are less reliable and open to a greater range of criticisms.

  • NB: In most cases, the arguments students will encounter as part of the Seminar Course will be INDUCTIVE.

Logical Fallacies & Evaluating Evidence

The Credibility of Evidence…

The first step in evaluating an argument is to identify the evidence or reasons upon which the conclusion relies and to ask whether they are credible, appropriate & complete/sufficient

Criteria of Credibility (RAVEN)

  • R = Reputation (Does the source’s history or status suggest reliability or unreliability?

  • A = Ability to See (Is the source in a position to know what they’re talking about?

  • V = Vested Interest (Has the source of information anything personally at stake?)

  • E = Expertise (Does the source have specialised knowledge & does the situation demand it?)

  • N = Neutrality (Is the source predisposed to support a particular point of view for reasons other than vested interest)

Lies, damn lies and…

  • When presented with observational evidence (e.g. data or statistics) to support a claim, we need to be wary. If we are told “A study has shown that…” then we should think twice before we accept the conclusion that is drawn from it.

  • The most basic mistake in interpreting evidence is simply misrepresenting the data - deliberate distortion (i.e. making up evidence), accidental misinterpretation, and selectivity.

  • A more common error is drawing a conclusion from insufficient data. Every study has a margin of error and the smaller the study the greater this will be.

  • A constant danger in empirical studies is unrepresentative data. A study that has a sufficient quantity of data may nevertheless be flawed due to insufficient quality of evidence.

The camera never lies…?

  • Images are often offered as concrete proof that a claim is true. However, there are three criteria that you need to bear in mind: relevance, significance, and selectivity.

  • For an image to support a claim, it must depict all of the key ideas contained in the claim. It doesn’t relate to any part of a claim, then it can’t prove the claim.

  • You must ask how much interpretation of the image is necessary; does the image speak for itself, or must we make assumptions about it in order for it to support the claim?

  • You must ask how representative the image is. You must ask whether the example in the image is typical. It may be that it has been carefully selected to support a point, when actually most examples would go against it.


  • Arguments may use analogies.

  • For example, a common argument for the existence of God suggests that if people recognise the existence of a designer from signs of complexity, order and purpose in a man-made object such as a watch, how much more should they recognise the existence of a Creator given the existence of greater degrees of complexity, apparent order and seeming purpose in the natural world?

  • Arguments by analogy rest on a comparison between two cases. They examine a known case, and extend their findings there to an unknown case. The argument is only as strong as that comparison. If the two cases are dissimilar in important respects, then the argument commits the weak analogy fallacy.

Logical Fallacies

  • People often rely on faulty or fallacious arguments when making a case.

  • The mark of a faulty argument is when the reasons do not directly support the conclusion given.

  • Some fallacies are very common, even persuasive, and are often employed by Politicians and Advertising Agencies to make a point, perhaps where no very strong argument exists…

  • Let us consider some of the most common logical fallacies…

1) Ad Hominem (AKA getting personal…)

Latin for “against the man”.

The ad hominem fallacy is the fallacy of attacking the person offering an argument rather than the argument itself.

Ad hominems can simply take the form of abuse (e.g. “don’t listen to him, he’s a jerk”) but any attack on irrelevant biographical details of the arguer rather than on his argument counts as an ad hominem, e.g.

“that article must be rubbish as it wasn’t published in a peer-reviewed journal”;

“his claim must be false as he has no relevant expertise”;

“he says that we should get more exercise but he could stand to lose a few pounds himself”.

2) Appeal to Authority

an argument that attempts to establish its conclusion by citing a perceived authority who claims that the conclusion is true.

In all cases, appeals to authority are fallacious; no matter how well-respected someone is, it is possible for them to make a mistake.

The worst kinds of appeal to authority are those where the alleged authority isn’t an authority on the subject matter in question.

Take, for example “Darwin’s theory of evolution is false; my pastor says so.” A pastor saying that a complex scientific theory is false doesn’t prove that it’s so, particularly if the pastor lacks a background in science.

3) Appeal to History

The first type of appeal to history is committed by arguments that use past cases as a guide to the future. This is the predictive appeal to history fallacy…

Just because something has been the case to date, doesn’t mean that it will continue to be the case. This is not to say that we can’t use the past as a guide to the future, merely that predictions of the future based on the past need to be treated with caution.

3. Appeal to History

  • The second type of appeal to history is committed when it is argued that because something has been done a particular way in the past, it ought to be done that way in the future. This is the normative appeal to history fallacy, the appeal to tradition…

    • The way that things have always been done is not necessarily the best way to do them. It may be that circumstances have changed, and that what used to be best practice is no longer. Alternatively, it may be that people have been consistently getting it wrong in the past. In either case, using history as a model for future would be a mistake.

4. Appeal to Popularity

  • The fallacy of arguing that because lots of people believe something it must be true.

  • Popular opinion is not always a good guide to truth; even ideas that are widely accepted can be false.

  • Take, for example, “Pretty much everyone believes in some kind of higher power, be it God or something else. Therefore atheism is false.”

5. Circular Arguments

  • Circular arguments are arguments that assume what they’re trying to prove. If the conclusion of an argument is also one of its reasons, then the argument is circular.

  • The problem with arguments of this kind is that they don’t get you anywhere. If you already believe the reasons offered to persuade you that the conclusion is true, then you already believe that the conclusion is true, so there’s no need to try to convince you. If, on the other hand, you don’t already believe that the conclusion is true, then you won’t believe the reasons given in support of it, so won’t be convinced by the argument.

  • E.g. “You can trust me; I wouldn’t lie to you.”

6. Necessary or Sufficient Conditions

  • Some arguments confuse necessary and sufficient conditions. Such arguments fail to prove their conclusions.

  • Take, for example, “People who don’t practice regularly always fail music exams. I’ve practiced regularly though, so I’ll be all right.”

  • Not having practiced regularly may be a sufficient condition for failing a music exam, but it isn’t necessary. People who have practiced regularly may fail anyway.

    • Necessary conditions are conditions which must be fulfilled in order for an event to come about.

    • Sufficient conditions are conditions whichwould explain an event, but which do not guarantee it.

7. Correlation not Causation

  • “Post hoc”, hasty generalisation or false cause…

  • committed when one reasons that just because two things are found together (i.e. are correlated) there must be a direct causal connection between them.

  • Often arguments of this kind seem compelling, but it’s important to consider other possible explanations before concluding that one thing must have caused the other.

  • Take, for example, “Since you started seeing that girl your grades have gone down. She’s obviously been distracting you from your work, so you mustn’t see her anymore.”

8. Inconsistency

  • An argument is inconsistent if makes two or more contradictory claims.

  • If an argument is inconsistent, then we don’t have to accept its conclusion because if claims are contradictory, then at least one of them must be false.

  • An argument that rests on contradictory claims must rest on at least one false claim, and arguments that rest on false claims prove nothing – even if we haven’t established which claim is false.

8. Inconsistency (2)

  • Take for example “Murder is the worst crime that there is. Life is precious; no human being should take it away. That’s why it’s important that we go to any length necessary to deter would-be killers, including arming the police to the teeth and retaining the death penalty.”

  • This argument both affirms that no human being should take the life of another, and that we should retain the death penalty. Until this inconsistency is ironed out of the argument, it won’t be compelling.

9. Specific to General

  • Arguments often use specific cases to support general conclusions.

  • For example, we might do a quick survey of footballers, note that each of the examples we’ve considered is vain and ego-centric, and conclude that they all are.

  • In order for a set of evidence to support a general conclusion, the evidence must meet certain conditions (it must be drawn from a sufficient number of cases, and the specific cases must be representative.)

  • Arguments that base conclusions on insufficient evidence commit the generalisation fallacy.

  • For example “Smoking isn’t bad for you; my grandad smoked thirty a day for his whole life and lived to be 92.”

10. Restricting the Options

  • Arguments which fail to consider all of the options, commit the restricting the options fallacy.

  • For example, “Many gifted children from working class backgrounds are let down by the education system. Parents have a choice between paying sky-high fees to send their children to private schools, and the more affordable option of sending their children to inferior state schools. Parents who can’t afford to pay private school fees are left with state schools as the only option. This means that children with great potential are left languishing”.

  • This argument fails to take into account all of the options available to parents. For the brightest students, scholarships are available to make private school more affordable, along with other options such as home-schooling…

11. Slippery Slope

  • The slippery slope fallacy is committed by arguments that reason that because the last link in the chain is undesirable, the first link is equally undesirable.

  • This type of argument is not always fallacious. If the first event will necessarily lead to the undesirable chain of consequences, then there is nothing wrong with inferring that we ought to steer clear of it. However, if it is possible to have the first event without the rest, then the slippery slope fallacy is committed.

    • For example “If one uses sound judgement, then it can occasionally be safe to exceed the speed limit. However, we must clamp down on speeding, because when people break the law it becomes a habit, and escalates out of control. For this reason, we should take a zero-tolerance approach to speeding, and stop people before they reach dangerous levels.”

12. Straw Man

  • Straw Man arguments are arguments that misrepresent a position in order to refute it. Unfortunately, adopting this strategy means that only the misrepresentation of the position is refuted; the real position is left untouched by the argument.

  • For example, “Christianity teaches that as long as you say ‘Sorry’ afterwards, it doesn’t matter what you do. Even the worst moral crimes can be quickly and easily erased by simply uttering a word. This is absurd. Even if a sinner does apologise for what they’ve done, the effects of their sin are often here to stay. For example, if someone repents of infanticide, that doesn’t bring the infant back to life. Christians are clearly out of touch with reality.”

13. And you too…

  • “Tu quoque” is Latin for “you too”.

  • The tu quoque fallacy involves reasoning that because someone or everyone else does something, it’s okay for us to do it. This, of course, doesn’t follow.

  • Sometimes other people have short-comings, and we ought to do better than them. We can be blamed for emulating other people’s faults.

  • For example “It doesn’t matter that I occasionally break the speed limit; everyone else does it.”

Group Activities (3)

  • In tables of 6 return to the Bob Geldof article given out for the first activity. Consider the credibility of the evidence it cites and highlight the presence of any logical fallacies.

  • During this 5 minute discussion each group will be given one common fallacy to work on. Once you receive it you should consider how to present it to students in the most stimulating and memorable way. This will involve finding or devising an example and then presenting it effectively! You have a maximum of 15 minutes.

Summing Up…

Deconstruction Deconstructed

Deconstructing Arguments for GPR

Taking a step back…

  • Deconstruction for GPR is NOT JUST Critical Thinking.

  • It also requires students to take a step back, weigh up the range of perspectives and their broader implications.

Different Perspectives

  • When presented with an argument, try asking…

    • What is the background of the author and what context was the argument developed within?

    • How has the argument been shaped by background and context?

    • Would the argument differ if it was put forward by somebody else or for a different purpose?

    • Have culture, religion, politics or other beliefs (including gender) shaped or impacted the argument?

    • Are the weaknesses of the argument been dictated by any of these factors?


  • Students also need to reflect on the wider significance of each perspective and the existence of different perspectives.

    • What does the existence of this perspective mean for social cohesion, future politics or progress on a particular project?

    • Do the conclusions reached have a wider (global, social, economic) significance?

    • Do the reasons cited support other or additional conclusions?

    • Is there a significant lack of evidence, knowledge or understanding in some area?

    • Is the fact that such reasoning persuades some people potentially worrying?

Beginning to develop counter-arguments…

This is, of course, the first step in beginning the process of reconstruction.

Establishing the nature and features of the perspective presented enables student(s) to construct an alternative perspective, which may be a foil for the partiality and weaknesses of the argument presented.

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