Reasoning Flashcards
What is the difference between Deductive and Inductive reasoning?
Give an example *chocolate
Associate both to the 2 major schools of reasoning.
Deductions refers to predicting specific things from general principles.
ex) Deduct candies from the bag, taking something specific from the general bag.
Deductive= Rationalist
Inductive reasoning is when you generalize from specific instance.
ex) One thinks ALL chocolate will taste good because you have had chocolate before.
Inductive = Empiricist
What is categorical syllogisms referring to? Who is connected to this? What did this person develop?
Why is it called perfect syllogism??
Categorical syllogisms are formal arguments in which a conclusion is drawn based on generalities stated in 2 premises.
Aristotle = formal logic.
All A are B
All B are C
Therefore, all A are C
This is called a perfect syllogism because the form always results in a valid conclusion.
When evaluating categorical syllogisms what steps must we follow:
When evaluating categorical syllogisms follow these steps:
1) Assume the premises are true
2) Evaluate whether the conclusion necessarily follows from the premises (validity)
3) Determine if premises are true (soundness)
If you have a valid argument, you can then go back to evaluate whether the premises are true. If they’re true, they’re sound argument.
What distinguishes a sound and valid argument?
A sound argument must be true. An argument can be valid but not sound.
What is needed for effective reasoning?
Soundness
All poodles are animals
All animals are wild
Therefore, all poodles are wild
Which of these premises is untrue?
Premise 2 is not true and arguments based on false premises cannot be sound, even if they’re valid.
Valid, sound, invalid but sound?
1) All republicans are conservative
All conservatives voted for McCain
Therefore, all republicans voted for McCain
2) All democrats are liberal
Some liberals voted for Obama
Therefore some democrats voted for Obama
1) valid, but not sound
Neither premise is true…
2) Invalid and not sound
What is the Atmosphere Effect?
This is an error of syllogism.
Consistency in premises and conclusion influence judgments of validity
ex:
Some of the men are tired
Some tired people are women, Therefore
some of the men are women
What is Belief Bias? What type of error is this?
This is a memory error.
Claiming a syllogism is valid because YOU believe the conclusion is true.
The following is INVALID. The truth of the conclusion is only PART of the effective reasoning.
ex:
All democrats are liberal
Some liberals voted for Obama
Therefore some democrats voted for Obama
Gerken’s Quiz:
All people taking this quiz are students in my cognitive class All students in my cognitive class can evaluate the validity of syllogisms Therefore, all the students taking this quiz can evaluate this syllogism
The syllogism above is
A) sound
B) valid but not sound
C) invalid
My hope is that the correct answer is now A. Previous experience teaching this material tells me that the second premise may not be true and thus the correct answer would be B. If you aren’t getting how my hypothetical responses map onto my hopes versus past experience, you will want to practice more.
All infants are selfish.
All selfish people are manipulative.
Therefore, all infants are manipulative.
Does this syllogism follow the form of Aristotle’s perfect syllogism?
a. yes
A is B
B is C
Therefore, A is C
All infants are selfish.
All selfish people are manipulative.
Therefore, all infants are manipulative.
Now evaluate this syllogism
Select one:
a. invalid
b. valid but not sound
c. sound
d. invalid but sound
c. sound
Some aliens are grays
Some grays are evil
Therefore some aliens are evil
What is the likely source of the error for someone mistakenly claiming this syllogism is valid?
a. alien mind control
b. confirmation bias
c. belief bias
d. atmosphere effect
d. atmosphere effect
Some aliens are grays
Some grays are evil
Therefore some aliens are evil
Evaluate this syllogism.
Select one:
a. valid but not sound
b. invalid and sound
c. invalid
d. sound
c. invalid
Conditional Syllogism is often referred to as what?
What type of argument is it? *major and minor premise
Often referred to as hypothetical syllogisms.
These are two-premise arguments.
The major premise is a conditional and the minor premise includes either the antecedent or the consequent.
What type of statement is a Conditional?
*Antecedent and Consequent
If P, then Q.
If I study, then I will get an A.
Antecedent: If
Consequent: Then I will get an A
For any given conditional, there are 4 types of evidence that can be gathered and inferred on.
1st evidence: Affirming the Antecedent.
Give an example of Affirming the Antecedent for the following:
“If I study, I will get an ‘A’”
Is this valid or invalid?
-I studied
For any given conditional, there are 4 types of evidence that can be gathered and inferred on.
1st evidence: Denying the Antecedent.
Give an example of Denying the Antecedent for the following:
“If I study, I will get an ‘A’”
Is this valid or invalid?
- I did not study
- Therefore I will not get an ‘A’
The second possible piece of evidence is that “I did not study.” This is called denying the antecedent because we are saying the antecedent did not occur.
The conclusion one would be tempted to make is “I will not get an A.” “I will not get an A” doesn’t necessarily follow from the evidence.
Invalid.