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The Monash Critical Thinking Study

Sample Teaching Materials: Aomt

Extract from Lab 4 Student Handout


Exercise 2

In this lab and the next, we will be looking at some of the arguments for and against the use of stem-cells in medical research. We will look at the first section of Chapter 3 in Singer's book, Life Before Birth, pp. 41-52.

1. Read through the introduction to the section (pp. 42-3, up to 'In thinking though the ethical issue …'). This provides some background information on stem-cells.

2. Before going on, try to make an initial judgement on the issue: do you think it is permissible to use stem-cells for purposes of medical research? (For or Against)

3. Now look at the next three paragraphs (pp. 43-5, up to 'Putting these factual questions aside …'). What is Bush's main argument concerning stem-cells? What is his conclusion? What are his premises? Write down a clear and concise statement of the argument.

4. A. Can you think of any objections to Bush's argument?
F. Can you think of any alternative arguments for the same conclusion?

Singer now discusses some objections to Bush's argument.:

5. The 'natural causes' argument. (pp. 45-6; 'Putting these factual questions aside …' to 'More often than not, they aren't even aware it ever happened')

What is Singer's argument? In what way would Singer's argument count against Bush's argument? Does it attempt to show that one of Bush's premises is false? Or that the conclusion does not follow from the premises? Write out a clear statement of Singer's objection.

F. Can you think of any objections to Singer's counter-argument?
A. What responses to those objections could be given? Are there any better objections to Bush's argument?
6. The argument from uniqueness. (pp. 46-7; 'Bush tells us that every embryo is unique …' to 'Why then should producing more unique children outweigh …')

What argument does Singer here suggest that Bush could be making? How does Singer respond to that argument?

F . Can the argument from uniqueness be defended against Singer's criticism? Can you think of any objections to Singer's counter-argument?
A. What responses to those objections could be given? Are there any other relevant arguments that support Bush's premise?
7. A religious argument. (pp. 47-9; 'Let's try again.' to 'Can't it be defended on secular grounds?')

Here Singer suggests that Bush might have a certain kind of reason for believing in one of the premises of his main argument. What is that reason? What would the argument be? How does Singer respond it?

A. What objections to the religious argument might there be? Should religious arguments play a role in politics? Are there any other arguments, based on religion that could be given for the same conclusion?
F. How might the objections to the religious argument be countered?

8. A non-religious argument (pp. 48-9; 'Bush does give another …' to 'Even so, if we really want to understand ….').

Here Singer describes a non-religious argument for Bush's main premise. What is that argument?

F. How might the premises of the non-religious argument be defended?
A. Can you think of any objections to the premises of this non-religious argument?

More on this next week ….


Extract from Lab 4 Tutor's notes

Preparation for Exercise 2

The aim of the next exercise is to begin looking at the arguments concerning stem-cell research discussed by Singer in Chapter 3. Students should have read this in preparation for the tutorial. Nonetheless, it might be a good idea to get them to read the first part of this section again at this point and then answer any questions about it and so on. See part 1. of Exercise 2. If your students are well prepared, you could skip this step.

Part. 2 of the exercise asks students to form an initial opinion about the use of stem-cells - either for or against. The idea is to split students up into two groups, those in favour of using stem cells in medical research and those against. There are different questions on the handout for each group, labelled F (for) and A (against).

The class as a whole (or in small groups) then works through the arguments in this section of Singer's book and attempts to put the arguments in standard form. The handout basically goes through the arguments one by one and has some guidance questions to help.

Having come up with a statement of each argument, there are then some further questions, labelled F (FOR) and A (AGAINST) on the handout. The idea is that students in the F group should try to come up with answers to the F questions, and students in the A group should come up with answers to the A questions (this as a class discussion exercise).

As you will see, the questions are reversed - students who initially said that stem-cell research was permissible (F) are asked to think of reasons why it might not be permissible, or of objections to Singer's counter-argument. Students in group A - those against the use of stem-cells - are asked to think of objections to Bush's argument, or to defend Singer's counter-arguments against potential objections. The idea is to get some 'open-minded' thinking going - students are being asked to consider arguments against their own view. By all means explain to the students that this is the intention behind the exercise.

One potential problem with this plan is that most students will opt for one group rather than another (probably the 'for' group) leaving just one or two students in the other group, feeling isolated and a bit ganged up on. If that happens, it might be better to just randomly assign students to one of the two groups. You might like to do that anyway, to avoid confronting students straight away with having to form a view and 'take sides'.

You should make it clear to students that the intention is not to prove any one wrong or right, or for there to be winners and losers. All students views are to be respected and treated seriously. The aim is to try, as a class, to consider both sides of the argument as fairly as possible. The idea of splitting the students into two groups and getting them to argue AGAINST their own view is just an exercise in 'playing devil's advocate'. Explain to the students that thinking of arguments against a view you find plausible is something people are not generally very good at. The exercise is aimed at giving them some practice at this difficult task.

Extract from Lab 5 Student Handout

ARGUMENT EVALUATION: WHAT MAKES AN ARGUMENT SUCCESSFUL?

Three main conditions an argument must satisfy in order for it to be successful:

1. Truth: All premises must be true

2. Justification: The premises must justify or support the conclusion

3. Completeness: All relevant arguments, for and against, should be considered.

1. TRUTH

If a premise given in support of a conclusion is not true, then the argument cannot be a successful one.

An argument with a false premise fails even if the conclusion is true or plausible.

Example 1: Not every great composer was Russian. Beethoven was a great composer and he was Australian, not Russian.

The truth or plausibility of the conclusion by itself tells you nothing about the success of the argument of which it is a part.

Evaluating premises

How do you make a judgement about the truth of the premises? Sometimes you will know whether the premises are true, sometimes you might not be sure. What do you do in that case? Here are some questions you could ask:

URBAN LEGENDS

The following claims are all taken from an 'urban legends' website.(www.snopes.com) Some are true, some are false. Which ones do you think are true and which false? How could you find out? For those you think are true, try to think of some evidence that would undermine the claim.

1. Those who go swimming less than one hour after eating will be taken by a cramp and drown.

2. Chewing gum takes seven years to pass through the human digestive system

3. The Nobel Foundation does not confer a prize for achievement in mathematics because the man who established it, Alfred Nobel, was upset that his wife was carrying on an affair with an eminent mathematician

4. Tapping the side of a soda can will prevent its contents from foaming over when you open it.

5. Water boiled in a microwave oven can suddenly "explode."

6. The Great Wall of China is the only man-made object visible from the moon.

7. A penny placed on the tracks will derail a train.

8. A tooth left in a glass of Coca-Cola will dissolve overnight.

2. JUSTIFICATION

For a set of premises to count as a good reason for a conclusion they must all be true and they must justify or support the conclusion. A set of premises justifies or supports a conclusion when the following condition is satisfied:

If all the premises are true, then the conclusion is true.

If this condition is not satisfied, then the argument cannot be a successful one, because the truth of the premises do not give a reason to think that the conclusion is true.

How can you decide whether this condition is satisfied? Here is one way (see Elements of Argument , pp. 45-7). Pretend that you do not believe the conclusion . Now ask yourself:

If I believed the premises, would that increase my degree of belief in the conclusion?

An argument in which the premises do not support the conclusion fails even if the conclusion is true or plausible.

Example: All things that have an engine need oil. Cars need oil. Therefore, cars have engines.

Although the conclusion is true this argument fails because the premise do not support the conclusion. Pretend that you did not know whether cars have engines or not (suppose you were an alien recently arrived on earth and knew nothing about it). Suppose that somebody tells you that the premises are true and you believe them. Should you now believe that cars have engines?

BIASES IN ASSESSING SUPPORT

Whether or not premises support a conclusion is independent of whether or not the conclusion is true or plausible. However, many psychological studies show that people are typically not very good at making judgements about whether premises support a conclusion independently of the truth of the conclusion. People tend to overweigh the evidence for a conclusion they already believe or know to be true - an example of myside bias.

These studies show that (on average) it is harder for people to correctly judge when premises do not support a conclusion when the conclusion is one they already believe. In the same way, it is harder for people to correctly judge that premises do support a conclusion when the conclusion is not one they already believe. This is something you should try to take account of when trying to decide whether the premises of an argument support or justify the conclusion. When assessing support, always pretend that you do not believe the conclusion, even when it is a conclusion you know to be true.

Exercise 1

For each of the following arguments, say whether the premises support the conclusion. That is, suppose the premises are true. Does it follow that the conclusion is true?

1. All things with four legs are dangerous. Poodles are not dangerous. Therefore, poodles do not have four legs.
2. All mammals walk. Whales are mammals. Therefore, whales walk.
3. All African countries are hot. Canada is not an African country. Therefore, Canada is not hot.
4. All things that are alive drink water. Televisions do not drink water. Therefore, televisions are not alive.

5. All nuts can be eaten. Rocks cannot be eaten. Therefore, rocks are not nuts.

6. All living things need water. Roses need water. Therefore, roses are living things.
7. All things made of wood can be used as fuel. Petrol is not made of wood. Therefore, Petrol cannot be used as fuel.
8. All bats have wings. Hawks are not bats. Therefore, Hawks do not have wings.

3. COMPLETENESS

In evaluating an argument you should always consider whether there are any other relevant arguments or considerations. It is your responsibility to consider not only objections to the argument, but also ways those objections might be countered.

It is also your responsibility as a rational evaluator, to consider additional arguments that might be relevant. Are there any further arguments for and against the conclusion? What other issues are related to this one? What arguments are there on these related issues?

SUMMARY

In evaluating an argument, always ask the following three questions:

The three questions of argument evaluation:

1. Are the premises true?
2. Do the premises support the conclusion?
3 . Are there any other relevant arguments or considerations?

Exercise 2

We continue our look at some of the arguments for and against the use of stem-cells in medical research, in Peter Singer, Chapter 3, Life Before Birth, pp. 41-52.

For each of the following passages, put the argument into standard form. The task is to then begin to evaluate the argument, using the above three questions.

In each case, try to say whether the premises of the argument are true and whether they support the conclusion, giving reasons for your answers. Then consider the third question: Are there any further arguments for and against? Can you think of any related issues and arguments? Is there anything Singer has missed?

8. The non-religious argument (pp. 48-9; 'Bush does give another …' to 'Even so, if we really want to understand ….').

Here Singer outlines an argument Bush might be giving against the use of stem-cells in medical research. What is that argument?

F. How might the premises of the non-religious argument be defended?
A . Can you think of any objections to the premises of this non-religious argument?

9. Why only human life? First attempt (p. 49; 'One possible ground … ' to ''… but not members of other races').

Singer now attempts to describe one argument that could be given in support of one Bush's main premises. He then gives an objection to that argument. Write out the supporting argument and Singer's objection to it.

F. Can you think of any objections to Singer's counter-argument? Can the supporting argument be defended? Why is it wrong to want to 'protect your own kind'? Does Bush's argument require the premise we should only protect are own kind or just the weaker claim that we should give preference to our own kind? How might that view be defended?

A. How might the objections to Singer's counter-argument be rebutted? Are there any other objections to Bush's argument?

10. Why only human life? Second attempt(pp. 49-50; 'A better answer is that …' to ' … when it befalls beings lacking that capacity').

Singer now suggests another way in which the premise of Bush's argument might be supported. What is the argument? Apply the three criteria of argument evaluation - are the premises true? Do they support the conclusion? Are there any other considerations?

A . Are there any objections to this new argument? Why should only beings with the mental capacities mentioned by Singer count as morally assessable?

11. A counter-argument (pp. 50-51; 'Bush, as we have seen, argued that …' to '…won't do that job'.

Singer now presents his objection to argument 3 above. What is his objection? Which of the three criteria of argument evaluation does Singer appeal to in rejecting Bush's argument?

F. How might Singer's objection be countered? Are there any other related arguments that could be given?

12. The argument from potential ( pp. 51-52, 'Is it relevant that the embryos Bush seeks to protect …' to 'Or should the government simply prohibit IVF ….?')

Singer now proceeds to describe a reformulation of Bush's argument, designed to avoid his own objection. What is the reformulated argument? Apply the three criteria for argument evaluation - how does the argument stand up?

Singer then provides two objections to the reformulated argument. What are these objections? Evaluate them by applying the three criteria.

F. Can Singer's objection be countered? Consider the second objection. Does the fact that a rule does not apply in general mean that it does not apply to any case? Is there a way of reformulating Bush's argument again, so that it survives his objections?
A. If there are any counter-arguments to Singer's objection, how might he defend his position? Are there any other arguments in support of Singer's conclusion?

Reading for next time; Singer Chapter 3: Capital Punishment, pp. 53-59

Extract from Lab 5 Tutor's Notes

... The next section of the handout is on justification, which corresponds to the validity of an argument. The important point to get across here, from the perspective of AOMT, is that an argument may be invalid, even though the conclusion is true or plausible. That is, in the terminology used here, the premises may not justify or support the conclusion, even though the conclusion is true or plausible.

There are some brief notes on how a failure to appreciate this point leads to certain kind of bias in evaluating arguments in the general population: if the conclusion is true or plausible, people will be more likely to over-estimate the strength of a arguments in favour of that conclusion. Go through the stuff on the handout with the students and try to explain the bias to them.

Exercise 1

The exercise that follows consists of some questions actually used in the research that demonstrates the existence of the bias. (You can let the students know this). The idea is just for them to say, in each case, whether the premises support the conclusion or not (whether the argument is valid or not).

In the AOMT literature there is the following idea about how to encourage students to think about the strength of an argument independently of prior belief. This is the PRETEND YOU'RE AN ALIEN rule. The idea is that you pretend you are an alien who has recently arrived on earth and someone is telling you certain things. You have a basic grasp of the grammar of the language, so you know what words like 'all', 'some' and so on mean. But you don't know anything else about cars, people animals and so on. So then you imagine you are told the premises of each argument and you believe them. To answer the question; do these premises support the conclusion, you then ask yourself should I now believe the conclusion, given that I believe the premises? The technique of pretending you are an alien is supposed to encourage you to think about the form of the argument, independently of your knowledge of the facts.

Exercise 2

Continuing with the analysis of Singer's arguments concerning stem-cells from last week. If you left off in the middle of the passages from last week and want to go back and finish off some of those, that's fine. Otherwise start again from the 'non-religious argument'.

The handout has the same format as last time, for each passage from Singer, students have to state the argument and then try to evaluate it. Again, there are different questions for the 'For' and 'Against' groups that you can use if you want to.

Try to get the students to apply the criteria discussed in this lab in giving their answers. Are the premises of the argument true? Do they support the conclusion? Are there any other relevant arguments or considerations? (See the SUMMARY on the handout).

Homework Assignment 2

Part I (20 marks total)

20 LSAT Logical Reasoning questions on identifying conclusions and makinf inferences.

Part II (10 marks total)

10 LSAT Logical Reasoning questions on assessing additional evidence. That is, identifying the statement that would if true, most undermine the given argument.

Part III (20 total)
Consider question 1 in Part II above. Explain in a sentence or two why the correct answer is correct, and why each of the incorrect answers are incorrect.

Part IV (50 marks total)
Over the last two weeks, we have looked at various arguments concerning stem cells. Choose a passage from Chapter 3 of Singer's book (not discussed in lab) which presents an argument dealing with stem cells and which you find convincing. (If you do not find any of the arguments convincing, choose the one that, in your opinion, is most powerful, if unsuccessful.) Please include the text of the passage with your answer.

Say what you think the premises and conclusion of the argument are.

Put yourself in the position of someone who is not convinced by the argument, and think of something they might say to try to undermine the argument.

What could you say in response to this imaginary critic that would neutralize, or weaken, their criticism?

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