National 5 Philosophy – Arguments in Action Revision Guide

This guide is here to help guide your revision for the Arguments in Action section for the National 5 Philosophy Exam. It is not exhaustive and you should use this alongside your class notes to help with your revision.

Candidates must be able to identify, explain and give examples of the following terms to show their understanding:

  • statement
  • argument
  • premise
  • conclusion
  • valid and invalid

Candidates must be able to:

  • distinguish statements from questions, commands, exclamations and arguments
  • identify premises and conclusions in an argument
  •  present an argument in standard form
  •  analyse simple arguments

Identify, explain and give examples of the following common fallacies:

  • attacking the person
  • false dilemma
  • illegitimate appeal to authority
  • slippery slope
Image result for statement command

Identify, explain and give examples of the following terms to show their understanding:

Statement

A sentence capable of being true or false (eg, the sky is blue). Statements are also known as propositions.

e.g. ‘The dog was brown’, ‘Peter was running.’, ‘war is wrong’, ‘apples can go rotten’.

Statements may express disagreements or arguments. We use them all the time and they make up the majority of our speech.

Statement Revision

 

Argument

A collection of statements (the premises) put forward to support a central claim (the conclusion).

I disagree with abortion because it is killing an unborn baby.

You will fail your exams if you do not study.

Argument Revision

Premise

A premise is a statement used in an argument to infer a conclusion. So premises are used to build up arguments which will eventually lead to a conclusion. If a sentence is expressing the main point of the argument which is trying to persuade you to accept then it is a conclusion. There are some key words or phrases you can look for which indicate something is a premise…

since, if, because, from which it follows, for these reasons,

Hidden Premises

Image result for hidden premise example

Sometimes a premise is so obvious that it doesn’t need to be stated at all. An important skill for any philosopher is to be able to be able to identify any unstated premises that an argument might be implying.

These unstated premises are called hidden premises. Arguments rely on them to be valid and so this is why we must identify them.

Dogs are dangerous. Therefore, dogs should be kept away from children.

Hidden Premise – Dangerous things should be kept away from children.

Conclusion

A conclusion is the final part of an argument which provides the outcome. The conclusion does not have to come at the end of a passage – unless they are using ‘standard form’. Look out for key words which might indicate a conclusion:

therefore, so, hence, thus, it follows that, as a result, consequently, and others!

“It’s flu season and you work with vulnerable adults, SO you should get a flu shot.”

Now, keywords like these make it much easier to identify conclusions, but not all arguments have keywords that flag the conclusion.

Standard Form

Arguments are often presented in Standard Form.

This is a consistent way of organising and presenting arguments which involves:

  •  identifying the premises and conclusions
  •  presenting the premises and conclusion as stand alone statements
  •  listing the premises and conclusion in a logical sequence (eg premise, premise, conclusion)
  •  drawing an inference bar between the premises and conclusion

Premise 1: I hate all vegetables

Premise 2: Carrots are vegetables

Conclusion: I hate carrots.

Standard Form Revision

Standard Form Video

True and False Statements

One very quick way of determining that an argument is unreliable is if one or more of the premise statements can be shown to be false. For example, the argument as follows is clearly unreliable because the first premise is false:

Barack Obama is French. All French people speak French. Therefore, Barack Obama speaks French.

Notice that simply because one or more premise statement is false it does not necessarily mean that the conclusion will be false. (In this case, Barack Obama might speak French, but not for the reasons we have given.)

What it does mean, however, is that the argument is unreliable. Remember: the purpose of an argument is to convince the listener that a particular statement (the conclusion) is true. Even if the conclusion does turn out to be true, but the argument rests on false premises, it is not a reliable argument.

Valid and Invalid

 

A valid argument is one which would guarantee a true conclusion if the premises were true. An invalid argument does not guarantee a true conclusion when the premises are true.

An invalid argument is one which is badly put together. With an invalid argument, the conclusion does not follow from the premises. Here is an example:

· P1 – All fish are animals.

P2 – All tigers are animals.

· C – Therefore, all fish are tigers.

Even though the first two statements are true, we can see that the conclusion is clearly false. This means the argument must be invalid because a valid argument will guarantee the truth of the conclusion if the premises are true.

Valid/ Invalid Arguments Revision

Deductive and Inductive Arguments

Image result for deductive and inductive

Deductive Arguments

An argument which attempts to prove certain conclusions based on what is contained in the premises alone.

Eg: All cats have tails. Felix is a cat, therefore Felix has a tail.

Inductive Arguments

Inductive arguments are based on evidence and attempt to reach a conclusion by generalising from this evidence.

P1 – Felix has a tail.

P2 – Felix is a cat.

C – Therefore, all cats have tails.

Inductive/ Deductive revision

Fallacies

Informal Fallacy

An argument, which may be formally valid yet is fallacious because it has false premises or ambiguous terminology or grammar.

Ad Hominem (Attacking the Person)

This fallacy is committed if it is argued that p is false on the ground that it is advanced by a particular person, for example because that person stands to gain from our acceptance of it as true or because that person’s behaviour is not consistent with the truth of p.

Image result for ad hominem example

 

False Dilemma

This fallacy is committed if, in the course of an argument, it is presumed without argument that p and q are the only two possibilities, when in fact there are other possibilities.

“Every nation in every region now has a decision to make. Either you are with us or you are with the terrorists.” George W Bush

Illegitimate appeal to authority

This fallacy is committed if a conclusion is inferred from the fact that some person or group asserts, without justifying the right of that person or group to be regarded as authoritative in this matter.

“Jenny McCarthy says that autism is caused by vaccines so I’m not going to get my child vaccinated!”

People use the arguments of Jenny McCarthy to suggest that autism is cause by vaccines. Jenny McCarthy is a model not a doctor or scientist so this is an example of an illegitimate appeal to authority.

Slippery Slope

An informal fallacy which claims that one thing will inevitably lead later to another, usually worse, state of affairs, without further argument.

“Hands free driving, cars that park themselves, an unmanned car driven by a search engine company. We’ve seen that movie. It ends with robots harvesting our bodies for energy.” Dodge Charger Advert

Other websites

https://www.futurelearn.com/courses/logical-and-critical-thinking#section-requirements

https://yourlogicalfallacyis.com/

 

 

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