Philosophy SACE Stage 2 Argument Analysis

Philosophy – SACE Stage 2 Argument Analysis

St John’s Grammar School

STAGE 2 PHILOSOPHY

Assessment Component 1

Argument

Name ______

David Rawnsley

Contents

Introduction

What is an argument?

Premises

Deductive arguments

Inductive arguments

Analysing arguments

Argument by analogy

Epistemology of Science

Glossary of terms

Bibliography

Introduction

Every discipline has its own methods for generating knowledge and solving problems. For example, mathematicians generate knowledge by working with the rules of mathematics to deduce new rules which still fit the mathematical frameworks. Problems are solved using the rules of mathematics in a logical way. In Science, scientists observe patterns of events and form rules to summarise their findings. Problems are solved through experimentation, observations and modification of the rules. In History, historians try to empathise with people and events to understand causes and consequences then develop coherent stories which explain the changes. Problems are solved through developing coherent stories which take in any new evidence.

How do philosophers develop knowledge? The problem solving tool of philosophers is argument. By this I don’t mean the type of arguments you might have with your parents about what time to be home on a Saturday night. I mean arguments which follow specific patterns and which use evidence to draw conclusions. There are three basic types of arguments which this unit will address: deductive arguments, inductive arguments and argument by analogy. Each of these arguments involves some specific concepts and some specific terminology.

This section will address argument by working through the following components.

1. What is an argument?

2. Premise propositions

3. Deductive arguments

4. Inductive arguments

5. Argument by analogy

What is an argument?

This question is well answered using the script from Monty Python.

“An argument is a connected series of statements intended to establish a proposition.”

An argument is where evidence is presented and a conclusion, in the form of a proposition, is drawn from the evidence. For example, consider the following three sentences.

1. Students who work hard during year 12 do well.

2. You are all students who will work hard this year.

3. You will all do well.

The first 2 sentences are statements used as supporting evidence and in philosophy we call them premises. The third sentence is a conclusion drawn from the evidence. Another example is shown below.

P1 Last Tuesday was a hot day.

P2 The Tuesday before that was a hot day.

C All Tuesdays are hot days.

Argument involves drawing a conclusion from some evidence. Consequently, there are two aspects to an argument.

Firstly, there is the evidence. This is usually presented in the form of propositions which we call premises.

Secondly, there is the conclusion which we draw from the evidence. Without the conclusion there is no argument. There is just some evidence or some propositions.

Consider the arguments below. In each case underline the evidence (premises) and put a circle around the conclusion. I have done the first one for you.

1. The stereo is on and the CD is playing so the sound should be coming through.

2. It will cost me $59 because the advertisement says that’s what they are selling them for and I want to get it at that shop.

3. I should get $2.80 change because the pie cost $2.20 and I gave them a $5 note.

4. We’ve had a roast every Sunday for lunch this year so I guess this Sunday we’ll have a roast too.

5. All year 12’s are required at the assembly. You are in year 12 so you should be there too.

6. It’s a seven lesson day and we’ve had five already so there must be two to go.

7. There is a low moving in from the bight and it will bring rain with it. It should reach Adelaide about 3 pm in the afternoon so we can expect rain then.

8. All zigwogs are nigwogs. Jig is a zigwog Jig is a nigwog

9. Road accidents often involve people driving too fast. Road accidents often involve people who drink alcohol. Road accidents often involve people who are tired. To avoid having an accident, it is best not to drive fast or to drive when you have been drinking alcohol or are tired.

How is an argument different from information?

Premises - propositions

To analyse an argument is to break it down into its component parts. A good way to start analysing arguments is to be able to identify the premises and the conclusions. As mentioned earlier, two things need to occur before we can say an argument is a good one. Firstly, the premises must be true and, secondly, the logic must be acceptable. A premise is simply a proposition – a statement which proposes some evidence which is the basis for the argument. How do we establish that the premises are true? This will be the focus of the next section.

Must all propositions be true or false? Are there some which are neither? Consider the four propositions below.

1. All triangles have three straight sides.

2. U2 play excellent music.

3. God exists.

4. Water boils at 48 degrees Celsius.

If these propositions are used as the basis for arguments then we would need to establish whether each is true or false. If a proposition is not true then it is not a very good basis from which to argue.

Only two of these statements can be considered true for a philosopher.

1. The first statement is true because it is a definition. ‘All bachelors are unmarried men’, would be another example. Definitions are true because of the meaning of the words in the sentence.

A stipulation is a similar but slightly different form of an analytic statement. In a stipulation a person may simply stipulate what they mean by a word or phrase;

e.g. “By a lot of rain I mean over 20 mm.”

“By speeding I mean going faster than 40 k/hr.”

Definitions and stipulations must obviously be true and are called analytical statements.

2. The second proposition is an opinion. It may appear true to the person who is saying it but that is about all the truth we can give it. A second person may well give a different opinion and say that their music is not excellent. Other examples could include, ‘Twilight is a terrific movie’, ‘Shane Warne is a great cricketer’ or ‘The Crows are the best football team’. These are examples of opinions and they cannot be regarded as either true or false. Consequently, it is important to recognise opinions in the premises of arguments because they cannot usually be assumed as acceptable evidence.

3. The proposition that God exists is an example of a Metaphysical statement. It is a statement which refers to something beyond our physical world and which is either true or false but which we are unable to prove. Other examples could include;

‘The world and our memories came into existence five minutes ago’,

‘Spirits live in rocks and trees’ and

‘People have a separate mind and body’.

Once again, it is important to recognise metaphysical statements if they appear in premises of arguments because they cannot be proven true. They can only be assumed true or false and this weakens an argument.

4. The final form or proposition is an Empirical statement. These are commonly found in science and can be tested to determine their truth or falsity. For example, to test whether the empirical statement, ‘It is cloudy outside’ is true we could go outside and see for ourselves. Other empirical statements could include, ‘Harry Potter is the highest grossing film in Australia’, Shane Warne has the highest wicket taking average of any Australian bowler’ and ‘The Crows won the 2004 AFL Premiership’. These propositions are empirical because they can be tested to determine their truth. If an argument contains empirical statements in the premises then we need to ascertain their truth as part of the analysis.

It is important to look at the premises in arguments carefully. Some premises can be shown to be true or false. Others must be assumed so, while the truth of others simply cannot be determined. For example, consider the arguments below.

P1 The concert will be by The Jets

P2 The Jets play excellent music.

C The music at the concert will be excellent.

(This argument rests on an opinion in Premise 2 and therefore is to be regarded as a weak argument, even though Premise 1 is empirical and can be proven true or false.)

P1 If God exists then we should worship Him.

P2 God exists.______

C We should worship God.

(This argument rests on a metaphysical statement in Premise 2 and, therefore, it is a weak argument. Premise 2 cannot be proven to be correct. What type of premise is Premise 1?)

P1 Pure water boils at 100 degrees Celsius at sea level.

P2 I will boil this pot of pure water at sea level.

C It will boil at 100 degrees Celsius.

(This argument rests on two empirical premises which can both be shown to be true or false. If they are both shown to be true then the argument is on the way to being considered a strong argument. We would still need to examine the second part of the analysis, that of the logic of the argument.)

Read the conversation below in which John, Megan and Peter discuss The Matrix. Examine each statement carefully and using a code of your own identify each statement as either an analytic, empirical, opinion or a metaphysical statement.

John The Matrix was a cool movie.

Megan I thought it was pretty ordinary. The sequel was better.

Peter What did John say?

Megan John said that The Matrix was cool.

Peter It’s had one of the highest gross takings of movies in the last few years.

Megan I don’t think that’s what John meant. By cool he meant that he enjoyed it.

John Neo was really cool. I like how he always stood up for what he believed.

Peter I didn’t understand what reality was in the movie.

Megan Reality for most people in the movie was what they experienced.

Peter Reality is always there and doesn’t rely on how I perceive it.

John We could all be like the people hooked up in the Matrix. We could be wired to understand what we are fed. We’d never know if this was the case.

Megan In the movie, Trinity understood what was real.

John By real you mean what she perceived.

In each of the three arguments below circle the conclusion and underline the premises.

Megan I enjoy all movies that make me think about my reality. The Matrix made me think about my reality. Therefore I enjoyed it.

Peter Well I haven’t seen the last sequel yet. I enjoyed The Matrix. I enjoyed The Matrix Reloaded. So I guess I’ll enjoy the final one too.

John I enjoy movies that make me feel as if I was there. I enjoyed all The Matrix series so I guess they all made me feel as if I was there.

Summary - premises

It is important to examine the propositions which are used as premises in an argument. Only propositions which can be proven true add significantly to the strength of the argument. Conversely, propositions which are false or which cannot be shown to be true or false detract from the strength of the argument.

However, it is not enough to only look at these propositions. The second part of analysing an argument involves evaluating the logic of the argument. Deductive and inductive arguments each have different forms of logic associated with them and so they will be addressed in turn. For each of these types of arguments it is essential to understand the logic and to be able to determine whether or not the logic of any particular argument is satisfactory.

Deductive arguments

Deductive arguments, often known as syllogisms, owe their origins to Aristotle. They are the only form of argument where we can say with 100% certainty that if the premises are true then the conclusion must be also. Consider the following examples and note the specific form of the arguments.

P1 Tommy is a cat.

P2 All cats are animals

C Tommy is an animal

P1 All bees are insects.

P2 The Queen Bee is a type of bee.

C The Queen Bee is an insect.

P1 All peaches are animals.

P2 All animals are fruit.

C All peaches are fruit.

Syllogisms such as these usually contain a statement which says that all of one group can be classified as another (All cats are animals, All bees are insects). They also contain a second premise which says that a particular thing is a member of the first group (Tommy is a cat, The Queen Bee is a type of bee). The conclusion is unavoidable and the particular thing must also be a member of the larger group.

In Mathematics syllogisms can be represented using Venn Diagrams. For example in the Venn Diagram below Tommy is shown as a particular within the circle of cats (premise 1). The cats are shown as being within the circle of animals (premise 2). It is obvious from this that Tommy is also an animal.

Use the Venn Diagrams on the right to represent the second and third arguments above.

Write 2 syllogisms of your own.