Philosophy Higher
Critical Thinking
Summary Notes
for
Study and Revision Purposes
What you need to be able to do to pass an assessment
Part 1 - Understanding the nature of arguments
Learning Intention – You should have learned what is meant by an argument in Philosophy and how
arguments are structured, plus that there are two types of argument
Success Criteria: You should now be able to do the following:
1. Explain what is meant by an argument in philosophy
2. Explain how arguments are structured
3. Explain the meaning of key words such as ‘refute’ ‘deny’ ‘deduce’ ‘infer’
4. Explain the different kinds of statements that can be used in an argument
5. Explain the difference between Deductive and Inductive arguments.
6. Give examples of deductive and inductive arguments
7. Identify the statements that form the premise(s) in an argument,
8. Spot the conclusion in an argument. i.e. The point of the person is trying to make
9. Explain what is meant by a hidden premise in an everyday argument.
10. Spot if any hidden premise is being used in an everyday argument.
11. Put the statement of the argument in brackets and number them then use an argument diagram to
clearly set out the way the argument is structured. i.e. (premise(s) and conclusion)
Part 2 - Reliable and unreliable arguments
Learning Intention: You should have learned what makes a good argument. You should have learned what is
meant by an argument being valid or invalid, sound or unsound, and what fallacies are and how they affect the
soundness of an argument.
Success Criteria: You should now be able to:
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Explain what is meant by validity and soundness. Give examples. Apply to an argument.
Give examples of a valid argument, a valid but unsound argument and a sound argument.
Use your intuition to decide if an argument is valid and sound
Test for validity using for example by using the Conditional Rule or a Venn diagram
Explain what a fallacy is and state what are the most common types.
Identify when a fallacy is being used in an argument
Higher Philosophy: Critical thinking
Part 1 - Understanding the nature of arguments
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An argument in philosophy is not a heated discussion. It is the presenting of reasons to either
support or refute a particular belief or idea. Arguments are used in everyday discussions. In
critical thinking we evaluate and analyse these arguments
Premises used in an arguments are statements (sentences) that can either be true or false
Statements can be distinguished from other sentences such as questions, instructions or
exclamations. Only statements are used in arguments.
Arguments can be deductive or inductive in type
Deductive arguments are made up of premises ( general statements). That should lead to a
conclusion
In everyday deductive arguments it is common for people to use a hidden premise. This is a
premise which is not stated but is assumed. If a hidden premise is used then the argument
cannot be valid.
An example of an everyday argument using a hidden premise
p1 Anyone who studies hard will pass their exams
Therefore Ryan will pass his exams
The Hidden Premise here which is no stated is hp2 Ryan will study hard
 When setting out an everyday argument in a formal way you need to put in the hidden premise
that is being used.
 Common types of statements used in deductive arguments are
A. If it is raining then I will take my umbrella. (statements called conditional)
B. ‘Either my car is red or my car is blue’
(either or statements)
C. ‘Paris is in Europe and Detroit is in America’
(statements called conjunctions)
D. ‘All birds have feathers’ ‘Some birds have feathers’ (statements called quantifiers)
 When evaluating everyday arguments you need to be able set them out formally to see exactly what is
being said. You need to be able to spot the conclusion and the statements (premises) which support it.
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An example of a Deductive argument
p1 Denny is in Scotland
p2 Scotland is in Europe
Therefore Denny is in Europe
Inductive arguments base a conclusion on premises derived from particular examples of evidence
or on past experience or observations These kind of arguments can be describe as weak or strong,
reliable or unreliable, probable or improbable. Inductive arguments are always invalid.
An example of an Inductive argument p1 The sun has risen every day for thousands of years
Therefore the sun will rise tomorrow
Part 2 - Reliable and unreliable arguments
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Valid arguments. In a valid argument the statements are closely linked in what is stated, there
are good connections between the various premises and the conclusion. If the premises are true
then the conclusion will be true. Valid arguments are said to guarantee the truth of the conclusion
or are truth preserving. Validity is not concerned with actual truthfulness.
For an example of a valid deductive argument see the one above.
Sound arguments are valid arguments in which the premises and the conclusion are all what we call
necessarily true (actually true in reality).
For an example of a valid and sound argument see the deductive argument above.
You can have a valid argument which is unsound.
An example of a valid but unsound argument
P1 All cats are ginger
P2 I have a cat
Therefore my cat is ginger
You cannot have a sound argument which is invalid
Fallacies are mistakes in the reasoning of an argument, they make the argument unsound even
though it may be valid. An informal fallacy renders a statement (or premise) not necessarily true.
Here are some of the most common fallacies used in everyday arguments:
a. Reasoning which assumes the conclusion in the premise (begging the question)
b. Reasoning which appeals to the slippery slope (Things will just get worse)
c. Reasoning which states that something causes something else without good reason
d. Reasoning which presents the listener with a false dilemma between two options
e. Reasoning which supports a point by attacking a person
f. Reasoning which appeals to irrelevant consequences
g. Reasoning that makes unjustified or illegitimate appeals to authority
h. Reasoning that assumes that if there is no evidence against a belief then it must be true
Remember philosophy is about truth. It is about what we can believe to be true. Only good reasoning
counts as rendering a belief or idea worthy of acceptance. Critical Thinking is a valuable personal skill.