Week 2: Critical Thinking
What is Critical Thinking?
The ability to apply the methods of logical reasoning/argumentation
Scepticism about the value of conventional ideas
- The refusal to accept mere opinion
- The capacity to resist one’s own cognitive biases
Also : A dedication to accepting answers that are supported by sound arguments
Logical Reasoning
• When we make claims we sometimes need to back these up with reasons to support
them
• When we do this, we are providing an argument for the claim we are making
• Logical reasoning involves giving good reasons to accept our arguments
STRUCTURE OF AN ARGUMENT
Any argument will be made up of two sorts of claims:
1. The conclusion : this is the claim you are giving reasons in support of.
The conclusion isn’t always given at the end of an argument. It can be the first statement.
2. The premise(s): these are the reasons you are giving to support your argument.
EXAMPLES
P1: Business Ethics is a Humanities course
C: I don’t need to study for Business Ethics
Arguments come in lots of shapes and sizes and we therefore make implicit (unspoken)
assumptions. It is helpful to formalise them by laying them out systematically.
- This helps us to see the relationship between the conclusion and premises (structure of
the argument) more clearly
- If we want to refute an argument, this also helps us to see where its problems lie
Validity of Deductive Arguments
Valid arguments are those which provide premises which if true, guarantee the truth of the
conclusion
• The conclusion follows from the premises
• The premises entail the conclusion
• If we assume the truth of the premises, then the conclusion would have to be true.
, THIS IS HOW TO TEST AN ARGUMENT FOR VALIDITY
Example 1 :
P1 : Socrates is a man P1: A=B
P2 : All men are mortal P2: B=C
C: Socrates is mortal C: A=C
Example 2:
P1 : If it is raining, there will be clouds in the sky P1: If A then B
P2 : It is raining P2: A
C: There are clouds in the sky C: B
MAKING ARGUMENTS VALID
To make an argument valid, we often must identify and include any
hidden/missing/suppressed premises:
• To link the other premises to the conclusion as directly as possibly
• Example : P1 : Business Ethics is a humanities course
P2 : Humanities courses are easy. It is impossible to fail humanities
courses P2: You do not need to study for humanities courses
C: I don’t need to study for Business Ethics
Valid Arguments can be absurd
P1: All apples are oranges P1: A=B
P2: All oranges are blue P2: B=C
C: All apples are blue P3: A=C
Are these arguments sound?
“ Commerce students are greedy because they want to make money, which is greedy”
- P1: Commerce students wants to make money
- P2: Wanting to make money is greedy
- C: Commerce students are greedy
“Commerce students are evil because they want to make money, and money is the root of
all evil”
What is Critical Thinking?
The ability to apply the methods of logical reasoning/argumentation
Scepticism about the value of conventional ideas
- The refusal to accept mere opinion
- The capacity to resist one’s own cognitive biases
Also : A dedication to accepting answers that are supported by sound arguments
Logical Reasoning
• When we make claims we sometimes need to back these up with reasons to support
them
• When we do this, we are providing an argument for the claim we are making
• Logical reasoning involves giving good reasons to accept our arguments
STRUCTURE OF AN ARGUMENT
Any argument will be made up of two sorts of claims:
1. The conclusion : this is the claim you are giving reasons in support of.
The conclusion isn’t always given at the end of an argument. It can be the first statement.
2. The premise(s): these are the reasons you are giving to support your argument.
EXAMPLES
P1: Business Ethics is a Humanities course
C: I don’t need to study for Business Ethics
Arguments come in lots of shapes and sizes and we therefore make implicit (unspoken)
assumptions. It is helpful to formalise them by laying them out systematically.
- This helps us to see the relationship between the conclusion and premises (structure of
the argument) more clearly
- If we want to refute an argument, this also helps us to see where its problems lie
Validity of Deductive Arguments
Valid arguments are those which provide premises which if true, guarantee the truth of the
conclusion
• The conclusion follows from the premises
• The premises entail the conclusion
• If we assume the truth of the premises, then the conclusion would have to be true.
, THIS IS HOW TO TEST AN ARGUMENT FOR VALIDITY
Example 1 :
P1 : Socrates is a man P1: A=B
P2 : All men are mortal P2: B=C
C: Socrates is mortal C: A=C
Example 2:
P1 : If it is raining, there will be clouds in the sky P1: If A then B
P2 : It is raining P2: A
C: There are clouds in the sky C: B
MAKING ARGUMENTS VALID
To make an argument valid, we often must identify and include any
hidden/missing/suppressed premises:
• To link the other premises to the conclusion as directly as possibly
• Example : P1 : Business Ethics is a humanities course
P2 : Humanities courses are easy. It is impossible to fail humanities
courses P2: You do not need to study for humanities courses
C: I don’t need to study for Business Ethics
Valid Arguments can be absurd
P1: All apples are oranges P1: A=B
P2: All oranges are blue P2: B=C
C: All apples are blue P3: A=C
Are these arguments sound?
“ Commerce students are greedy because they want to make money, which is greedy”
- P1: Commerce students wants to make money
- P2: Wanting to make money is greedy
- C: Commerce students are greedy
“Commerce students are evil because they want to make money, and money is the root of
all evil”
