Argument Analysis

1. Argument Analysis By: Chelsea Abreu

2. Identifying Arguments • What is an argument? • To give an argument is to provide a set of premises as reasons for accepting the conclusion. To give an argument is not necessarily to attack or criticize someone. Arguments can also be used to support other people's viewpoints. • How to look for arguments: • There are no easy mechanical rules, and we usually have to rely on the context in order to determine which are the premises and the conclusions. But sometimes the job can be made easier by the presence of certain premise or conclusion indicators.

3. Validity and Soundness • Definition of validity • The idea of validity provides a more precise explication of what it is for a conclusion to follow from the premises • Showing that an argument is invalid • we are defining a valid argument as an argument with no possible invalidating counterexamples.

4. Patterns of Valid Arguments • Introduction • With valid arguments, it is impossible to have a false conclusion if the premises are all true. Obviously valid arguments play a very important role in reasoning, because if we start with true assumptions, and use only valid arguments to establish new conclusions, then our conclusions must also be true

5. A03.2 Modus ponens Consider these arguments: • If this object is made of copper, it will conduct electricity. • This object is made of copper, so it will conduct electricity. • If there is no largest prime number, then 510511 is not the largest prime number. • There is no largest prime number. Therefore 510511 is not the largest prime number. • If Lam is a Buddhist then he should not eat pork. Lam is a Buddhist. • Therefore Lam should not eat pork. • These three arguments are of course valid. Furthermore you probably notice that they are very similar to each other. What is common between them is that they have the same structure or form. This is what helps build patterns in arguments.

6. Identifying Hidden Assumptions • When people give arguments sometimes certain assumptions are left implicit • Someone who gives such an argument presumably has in mind the hidden assumption that whatever that is unnatural is wrong. It is only when this assumption is added that the argument becomes valid. • In everyday life, the arguments we normally encounter are often arguments where important assumptions are not made explicit. It is an important part of critical thinking that we should be able to identify such hidden assumptions or implicit assumptions.

7. How should we go about identifying hidden assumptions? • Two Main Steps: • determine whether the argument is valid or not. If the argument is valid, the conclusion does indeed follow from the premises, and so the premises have shown explicitly the assumptions needed to derive the conclusion. • ask questions such as : • (a) what do these assumptions mean? • (b) Why would the proponent of the argument accept such assumptions? • (c) Should these assumptions be accepted?

8. Inductive Reasoning • What is induction? • the conclusion is highly likely to be true given that the premises are true Three main differences between an inductively strong argument & a valid argument: As already noted, in a valid argument, the conclusion follows logically from the premises, but this is not the case in an inductively strong argument. It is logically possible for the premises to be true while the conclusion is false. Deductive validity is not a matter of degree. An argument is either deductively valid, or it is not. But inductive support is a matter of degree, depending on the probability of the conclusion being true given the premises. A related point is that inductive strength is defeasible, whereas validity is not. To say that validity is not defeasible is to say that if you have a valid argument, adding new premises will not make it invalid. If it is indeed true that three people have died, then it follows that at least two people died, and this will remain the consequence whatever new information you acquire.

9. Good Arguments What is a good argument? • Criterion #1 : A good argument must have true premises • This means that if we have an argument with one or more false premises, then it is not a good argument. Criterion #2 : A good argument must be either valid or strong Criterion #3 : The premises of a good argument must not beg the question Criterion #4 : The premises of a good argument must be plausible and relevant to the conclusion

10. Argument mapping An argument map is a diagram that captures the logical structure of a simple or complex argument. In the simplest possible case, we have a single premise supporting a single conclusion Consider this argument : Life is short, and so we should seize every moment. This can be represented in an argument map as follows:

11. Conclusion Arguments play a huge role in writing today. People are always trying to defend their side and persuade other to accept their perspectives. These tips and ideas on how to mold a good argument could be very beneficial for people. In order to portray your message you must know how to organize what you are trying to get across. We can’t just use, ‘I am right, just because I’m right’ as an argument. Argument analysis teaches you how to back up and defend your ides.