Critical Thinking

In an argument, main premises such as 1. or 2. are often supported by sub-premises in a sub-argument. Which of the following could be the number of a premise supporting a main premise?

1.1

The next three questions all relate to following argument: C: Some farmers in the Murray basin are likely to suffer serious financial problems over the next few years 1. If the currently very high levels of salinity in the soil around the Murray are not reduced, the land in some areas will become useless for crops. 2. The problem of salinity is unlikely to be solved in the near future. If you added the following claim as a premise or sub-premise, where would be best placed? You can indicate this by choosing the appropriate premise or sub-premise numbering for it (e.g. would it be 1.1? 3? 2.2? etc. "Crops will not grow in areas with very saline soil."

1.1

Which of the following are true statements about premises that are numbered 1.1 and 1.2 in the standardisation of an argument? (Choose all that are true). Select one or more: a. They are on the same level. b. They are on different levels. c. They can be linked or convergent. d. They are part of different sub-arguments.

A & C

A sub-premise numbered 1.2. is:

A sub-premise supporting premise 1.

Is the following best understood as an argument, an explanation or neither? Ethanol couldn't be too harmful for car engines. Otherwise the government would have legislated against its use as a petrol additive.

Argument

Is this best understood as an argument or an explanation? "Your son has been arrested. He was caught trying to steal a car."

Explanation. No attempt is made to convince you of anything, it is just an explanation of why your son has been arrested.

Is this best understood as an argument or an explanation? "Many sailors in the 18th century suffered from scurvy, because their diets were lacking in vitamin C."

Explanation. No attempt is made to convince you of anything. It is an explanation of why the sailors suffered from scurvy.

Is the following passage an argument or an explanation? "The penalty for speeding involves demerit points, as well as a fine. This is so that those who can afford to pay large fines cannot keep speeding without disadvantage."

Explanation. The point of the passage is to explain why it is that the penalty involves demerit points as well as a fine, not to convince you that this is so.

A passage is an argument if and only if it contains indicator words such as "therefore", "because" or "so". True or false?

False.

If a passage is an argument, whatever follows "thus", "so", or "therefore" will always be the conclusion. True or False?

False. It's not always the case.

In the following argument, what is the conclusion? Despite popular opposition in the UK, Fox hunts should be allowed to continue because of tradition, and because it is a good means of pest control.

Fox hunts should be allowed to continue.

In the following argument, identify which statement is best understood as the conclusion. "Heart disease is one of the most significant causes of death in Australia. More money should be put into preventative programs."

More money should be put into preventative programs. The fact that it is a significant cause of death is given as a reason for thinking that we should fund preventative programs.

Is the following best understood as an argument, an explanation or neither? Koalas only eat eucalyptus leaves. Despite land clearing, however, there are still plenty of eucalyptus trees throughout Australia.

Neither

An argument has two main premises, 1 and 2. If premise 1 were removed, would the conclusion still be supported?

Only if 1 and 2 were convergent premises.

Give examples of conclusion indicators.

So, hence, therefore, thus

The principle according to which we should interpret a passage in such a way that it makes most sense, and is most likely to be faithful to the author's intentions is:

The principle of charity

Is the following best understood as an argument, an explanation or neither? The detainees rioted because they were frustrated about the time taken to process their applications.

Explanation

Is this passage an argument, an explanation, or neither? Abe did the sample quiz because he realised that it would help prepare for the real quiz.

Explanation

In the following argument, identify which statement is best understood as the conclusion. "Mobile phones are unlikely to pose a serious health risk. There is no conclusive link between radiation from phones and brain tumours."

Mobile phones are unlikely to pose a serious health risk. The lack of evidence is given as a reason for thinking that there is not significant risk.

If a passage cites the causes of the phenomenon described in the main point, it is probably an explanation. True or false?

True.

Two premises will be linked or convergent if and only if they are on the same level. True or False?

True.

Premises are the reasons or evidence given to convince an audience of the conclusion.

True. Premises provide reasons or evidence.

Returning to the previous argument: C: Some farmers in the Murray basin are likely to suffer serious financial problems over the next few years 1. If the currently very high levels of salinity in the soil around the Murray are not reduced, the land in some areas will become useless for crops. 2. The problem of salinity is unlikely to be solved in the near future. If you added the following claim as a premise or sub-premise, where would be best placed? You can indicate this by choosing the appropriate premise or sub-premise numbering for it (e.g. would it be 1.1? 3? 2.2? etc. "Current farming practices would need to be changed dramatically for salinity to be reduced."

2.1

Is the following passage and argument or an explanation? "Some muskrats are not nocturna, for naturalists who have studied the habits of these animals have determined that there is evidence of muskrats feeding during the day and sleeping at night."

Argument

A good argument is one which has a conclusion which is at least as likely to be believed as the premises. True or False? Why or Why not?

False. A good argument will very often have a conclusion which is less likely to be believed than the premises. The point of the argument is often to try to convince you of that more surprising proposition, by showing that it follows from things you already believe. You can re-check Section 4 and 5 from the topic notes this week if you like. The comparison between explanations and arguments may be helpful here.

Consider the following argument: If you are not an electrician, you should not do your own electrical work, since electricity is very dangerous if you don't know what you're doing, and your insurance won't cover damage to your house caused by electrical fires if the work was not conducted by a licenced electrician. The conclusion here is "If you are not an electrician, you should not do your own electrical work" The premises are "electricity is very dangerous if you don't know what you're doing" "your insurance won't cover damage to your house caused by electrical fires if the work was not conducted by a licenced electrician" How should the premises should be standardised?

1 and 2, and they are convergent.

Returning to the previous argument: C: Some farmers in the Murray basin are likely to suffer serious financial problems over the next few years 1. If the currently very high levels of salinity in the soil around the Murray are not reduced, the land in some areas will become useless for crops. 2. The problem of salinity is unlikely to be solved in the near future. If you added the following claim as a premise or sub-premise, where would be best placed? You can indicate this by choosing the appropriate premise or sub-premise numbering for it (e.g. would it be 1.1? 3? 2.2? etc. "The prices received by Australian farmers for many crops are getting lower and lower."

3

How many separate inferences will there be in an argument with linked premises 1 and 2, convergent premises 1.1 and 1.2, and linked premises 2.1 and 2.2.

4

Is the following passage an argument or an opinion? "Nearly 30% of the people we asked about their personal beliefs said that they believed that extra-terrestrials had visited the earth. This shows that a large number of people do believe in aliens."

Argument Although there is mention of opinions and personal beliefs, facts about those beliefs are being used to argue for a conclusion, and convince us of a claim. This makes it an argument.

Is the following passage an argument or an explanation? The penalty for parking illegally, like the penalty for speeding, should involve demerit points. Otherwise those people who can afford to keep paying large fines can park wherever and whenever they want, and the rest of us must suffer.

Argument This is an argument, because the point of the passage is to convince you that something should be done - in this case, that the penalty for parking illegally should be changed. As a rule of thumb, you will often find that when the main point is asserting that something should be done, the passage will be an argument rather than an explanation.

Is this best understood as an argument or an explanation? "You should eat more fruit. Lack of vitamin C gives you scurvy"

Argument. As here, the word "should" often indicates the conclusion of an argument. It is also trying to convince you to eat more fruit.

How should this argument be standardised? You shouldn't take Billy to the circus. He doesn't approve of animals being kept in cages and he's afraid of clowns. Select one: a. Standardisation: 1 Billy doesn't approve of animals being kept in cages. 2 He's afraid of clowns C: You shouldn't take Billy to the circus. (with 1 and 2 as LINKED premises) b. Standardisation: 1 Billy doesn't approve of animals being kept in cages. 2 He's afraid of clowns C: You shouldn't t ake Billy to the circus.(with 1 and 2 as CONVERGENT premises) Right. The premises are convergent, since they offer independent support for the conclusion. c. Standardisation: 1.1 Billy doesn't approve of animals being kept in cages. 1 He's afraid of clowns C: You shouldn't take Billy to the circus. d. Standardisation: 1.1 Billy's afraid of clowns 1 Billy doesn't approve of animals being kept in cages. C: You shouldn't take Billy to the circus.

B

Which of the following are true statements about premises that are numbered 1.1 and 2.1.1 in the standardisation of an argument? (Choose all that are true). Select one or more: a. They are on the same level. b. They are on different levels. c. They can be linked or convergent. d. They are part of different sub-arguments.

B & D

In the following argument, identify which statement is best understood as the conclusion. "Bill answered fewer questions than anyone else. Bill is the weakest link."

Bill is the weakest link. The fact that he answered fewer questions than anyone else is supposed to convince you that he is the weakest link

In the following argument, identify which statement is best understood as the conclusion. "Bill should be voted out. Bill is the weakest link."

Bill should be voted out. His being the weakest link is a reason for voting him out.

What is the most likely standardisation for an argument of the form: A, because B and C. Additionally D, because E. So F.

C: F 1:A 1.1: B 1.2: C 2: D 2.1:E

"It will be useful for you to be able to standardise arguments." Which of the suggested statements could not offer support for this conclusion?: a) Being able to standardise arguments is a requirement of the course. b) It is important to practice standardising arguments. c) Standardising arguments will be make them easier to evaluate. d) Standardising helps to clarify the role of the different parts of an argument.

It is important to practice standardising arguments.

Although the last Harry Potter movie was popular, the Lord of the Rings was the most successful movie that year. It out sold Harry Potter by 2 to 1.

LOTR was the most popular movie of the year.

If two or more premises are connected, and must be taken together to support the conclusion, they are:

Linked

Are the premises of this argument linked or convergent? Craig has experience as a banker. He has a degree in economics. The bank is looking for a candidate with experience and academic qualifications. So Craig has the qualities they are looking for.

Linked.

In the following argument, identify which statement is best understood as the conclusion. "Now would be a bad time to put the washing out. It's raining."

Now would be a bad time to put the washing out. The fact that it is raining is a reason to believe it would be a bad time to put the washing out.

Is the following passage an argument or an opinion? "I know its probably controversial, but I'd say chocolate is overrated. Its just cocoa beans and sugar. People carry on as though its nectar of the Gods or something".

Opinion Its offering a personal belief, and it isn't really worried about giving reasons. If you challenge this person with alternative views or facts, they probably won't feel compelled to give up their belief.

Which of the following is a true statement about sub-premises 1.2 and 2.2 in an argument:

The subconclusions they support may be linked.

In the following argument, identify which statement is best understood as the conclusion. "We should try harder to avoid damaging the environment. We should recycle more."

We should recycle more. Often a sentence containing "should" is likely to be the conclusion, but here both sentences do. The claim that we should avoid damaging the environment in general is given as a reason for thinking that we should recycle more.

An argument has three main premises: 1, 2, and 3. Premises 2 and 3 are linked, and premise 1 is convergent with them. If one of the premises were removed, would the conclusion still be supported?

Yes. The fact that 2 and 3 are linked, but 1 is convergent with them means that the conclusion has two inferences supporting it: one from 1 to C, and one from 2 and 3 to C. So if premise 1 were removed, then the conclusion would still be supported by 2 and 3, and if either 2 or 3 were removed, the conclusion would still be supported by 1. So whichever single premise is removed, the conclusion still has another good inference.

In the following argument, what would be the best formulation of the conclusion. "You said that you would pay me $20 if I washed your car, and I have, so pay up!"

You should pay me $20.

Of the following pairs of premise numbers, which would indicate that the first is a premise in support of the second? (You may select more than one answer). Select one or more: a. Premises numbered 1.1 and 1 b. Premises numbered 2.2 and 2.2.1 c. Premises numbered 3.1 and 3.2 d. Premises numbered 3.1.2 and 3.1

a

Of the following sets of premise numbers, which would seem to be functioning as a sub-argument? (You may select more than one answer). Select one or more: a. 1.1 ... 1.2. ... 1. ... b. 1.2. ... 2.2... 3.2. c. 3.1. ... 3.2. ... 3.3. ... d. 1. ... 2. ... C: ....

a

What is the best way of standardising the following argument? "Hockey is a middle class sport. Its played by rich kids - just look at the income of the schools where is played - and it has no popular following amongst the working class." Select one: a. 1.1 It is played at wealthy schools 1. Its played by rich kids 2. It has no significant working class following. C: Hockey is a middle class sport. Yes, that's right. b. 1. It is played at wealthy schools 2. Its played by rich kids 3. It has no significant working class following. C: Hockey is a middle class sport. c. 1.1 It is played at wealthy schools 1.2. It has no significant working class following. 1. Its played by rich kids C: Hockey is a middle class sport.

a