Critical reasoning/Readings/Reading 3

= TOPIC 3: Identifying and analysing arguments   =

As part of your induction process into critical reasoning, we would like to introduce you to Socrates, Plato and Descartes, three well-known and famous philosophers, and Thrasymachus, a relatively unknown thinker and exponent of the sophists, who became famous in Athens during the 5th century BC:

As you can see from their pictures, the gentlemen were born quite some time before you drew your first breath. However, their arguments form part of the classic history of the subject field Philosophy and as such you will see them in action below.

What is an argument?
The second transcript below is a discussion, recorded in Plato’s Republic, between Socrates and Thrasymachus, on what is just and right:

Transcript 2

Thrasymachus:''... I say that “right” is the same thing in all states, namely the interest of the established ruling class; and this ruling class is the “strongest” element in each state, and so if we argue correctly we see that “right” is always the same, the interest of the stronger party.''

Socrates:''... You say that obedience to the ruling power is right and just?''

Thrasymachus: I do.

Socrates: And are those in power in the various states infallible or not?

Thrasymachus: They are, of course, liable to make mistakes.

Socrates: When they proceed to make laws, then, they may do the job well or badly.

Thrasymachus:I suppose so.

Socrates: And if they do it well the laws will be in their interest, and if they do it badly they won’t, I take it.

Thrasymachus: I agree.

Socrates: But their subjects must obey the laws they make, for to do so is right.

Thrasymachus: Of course.

Socrates: Then, according to your argument, it is right not only to do what is in the interest of the stronger party but also the opposite.

Thrasymachus:What do you mean?

Socrates:''My meaning is the same as yours, I think. Let us look at it more closely. Did we not agree that when the ruling powers order their subjects to do something they are sometimes mistaken about their own best interest, and yet it is right for the subject to do what his ruler enjoins?''

Thrasymachus:I suppose we did.

Socrates: ''Then you must admit that it is right to do things that are not in the interest of the rulers, who are the stronger party; that is, when the rulers mistakenly give orders that will harm them and yet (so you say) it is right for their subjects to obey those orders. For surely, my dear Thrasymachus, in those circumstances it follows that it is right to do the opposite of what you say is right, in that the weaker are ordered to do what is against the interest of the stronger.''

The first transcript is an example of the meaning of the term “argument” according to sense (2) above. In other words, “argument” used in this sense means a group of statements intended to establish the truth of a claim. The second extract is an example of the meaning of “argument” according to sense (3) above. That is, “argument” used in this sense means an exchange or debate between two or more people who disagree with each other, in which each person gives reasons to support his or her position.

We will concern ourselves mostly with arguments in the sense of (2) in the sections which follow.

Here is a definition of an argument:

An argument is a group of statements. One of these statements is the conclusion of the argument. The other statements are the premises that are intended to convince the reader that the conclusion is true.

In the next study section we will explore what premises and conclusions are and we will identify premises and conclusions in arguments. You will also have the opportunity to apply the knowledge and skills you have gained by analysing arguments on your own.

Identifying premises and conclusions
Before we can identify premises and conclusions in arguments, we need to know what is meant by “premise” and “conclusion”.

Premises &amp; Conclusions
Premises are those statements in an argument that have the function of supporting the conclusion. Premises therefore provide reasons for accepting the conclusion of an argument, although not all reasons are good reasons or relevant reasons. Conclusions are those statements in an argument which the premises are intended to support. The purpose of an argument is to establish the truth or acceptability of the conclusion. A sound argument is one in which the conclusion is shown to be true or acceptable because it follows from the truth or acceptability of the premises and the valid structure of the argument.

Let us look at the following argument to explain what premises and conclusions are:

'''My nose itched this morning. So I am going to be upset later today.'''

In this argument the first statement is a premise and the second statement is a conclusion. It is obvious that the conclusion is not supported by the premise. There is no relation between my being upset later today and the fact that my nose itched this morning. When we analyse arguments it is important to identify premises and conclusions clearly.

In the online references you will find a detailed discussion on how to identify premises and conclusions in arguments. Study the relevant sections carefully and complete the activity that follows:

The structure of arguments
A full analysis of an argument not only identifies which statements are premises and which are conclusions, but also identifies the structure of the argument. The structure shows how the conclusion of an argument is related to its premises. Note that premises and conclusions are related to each other in different ways in various arguments. Sometimes a premise supports the conclusion independently; at other times the premises support the conclusion interdependently. You will find more information about the structure of arguments in the online references. Here we will only explain briefly the two different ways premises and conclusions are related to each other, by giving you two examples.

The following is an example of a simple argument, where the premises support the conclusion independently:

''Abortion preserves the mother’s rights over her own body. It also prevents the birth of unwanted children. Therefore, abortion should be made legally available.''

Let us bracket and number the statements of the above argument:

[Abortion preserves the mother’s rights over her own body].1

[It also prevents the birth of unwanted children] 2.

Therefore, [abortion should be made legally available]3.

Statement 1 supports the conclusion independently of statement 2 (assuming it is true or acceptable) and statement 2 supports the conclusion independently of statement 1 (assuming it is true or acceptable). We can represent the structure of this argument in the following way:



Now, let us take an example of a simple argument in which the premises support the conclusion interdependently.

All human beings are mortal. Sue is a human being. Therefore, Sue is mortal.

Let us bracket and number the statements of the above argument:

[All human beings are mortal]1. [Sue is a human being]2. Therefore, [Sue is mortal]3.

Statement 1 and statement 2 support the conclusion interdependently. Statements 1 and 2 together conclusively support the conclusion (assuming that both premises are true or acceptable).

We can represent the structure of this argument in the following way:



Note: Not all arguments are complete. Sometimes an argument has a missing premise. A full analysis of an argument requires us to fill in the missing premise. A premise is missing in an argument if, without it, the premises do not provide sufficient support for the conclusion, given that the premises are true. For example:

John is a poor student because he spends his time reading comic books and magazines.

This argument requires the further premise:

 Students who spend their time reading comic books and magazines are poor students

in order for the premises to provide sufficient support for the conclusion, given that the premises are true.Fully stated, the argument is as follows:

''Students who spend their time reading comic books and magazines are poor students. John spends his time reading comic books and magazines. Therefore, John is a poor student.''

Remember that if we accept the premises of an argument, and also accept the validity of the structure of the argument, then we are logically compelled to accept the conclusion. Conversely, if we do not accept the conclusion of an argument, then we are logically compelled to deny the truth or acceptability of at least one of the premises, or we are logically compelled to deny the validity of the structure of the argument. Sometimes you will want to say that both the premises and the structure of the argument are unacceptable.

Finally, an argument may imply its conclusion, rather than fully state it. In these cases we have to supply the implied conclusion in the same way that we have to supply the missing premises in an argument which is not fully stated.

In this section we have explored the idea that an argument has a structure. The way in which we evaluate an argument depends, partially, on its structure. Through practice and experience you will become aware of the structure of arguments and you will therefore find it unnecessary to portray arguments in diagrammatic form.

Applying your knowledge and skills to analysing arguments
You will hardly believe it, but if you have actively participated in your initiation process of becoming a critical thinker, you will now be at the stage where you have the competence to analyse arguments.

Here is a summary of the steps in argument analysis:

Step one — Clarify the meaning of the argument. Step two — Bracket and number the statements and underline the signal words. Step three — Identify the conclusion(s) of the argument. Step four — Identify the premises of the argument. Step five — Provide a representation of the structure of the argument.