Lecture 9, CH.7 - Pseudoreasoning Flashcards
What are Fallacies?
Fallacies are bad arguments:
- They consist of premises and conclusions, but don’t have good evidence to believe the conclusion (because the reasons that support a claim (conclusion) fail to do so).
- Consist of:
~ Formal Fallacies
~ Substantive fallacies
- Arguers are often aware of their fallacies, but might use the fallacy to persuade others in favor of their argument
Formal Fallacies
What are Formal Fallacies?
Formal Fallacies are arguments that are invalid:
!!! There is a failure in the logical connection between the premises and the conclusion !!!
What are the different types of Formal Fallacies?
- Affirming the Consequent
- Denying the Antecedent
- Deriving ‘ought from is’
- Base Rate Fallacy
- Undistributed middle fallacy
Formal Fallacies
What is the fallacy of affirming the Consequent and why is it a fallacy?
P1) If P then Q
P2) Q
C) P
Reason for fallacy: e.g. P: Philosopher, Q: Wise. If you are wise you are not also necessarily a philosopher, you can be wise and the reason for your wisdom may be due to many things
Formal Fallacies
What is the fallacy of Denying the Antecedent and why is it a fallacy?
P1) If P then Q
P2) Not-P
C) Not-Q
Reason for fallacy: Again, say P: Philosopher, Q: Wise, even if you are not a philosopher, that doesn’t mean you are definitely not wise. You might not be a philosopher and still be wise
Formal Fallacies
What is the fallacy of deriving ought from is?
P1) British Monarchy has existed for 1.000 years
C) British monarchy should be retained
NOTE: P1) is a descriptive premise (it just describes a situation) and C) is a prescriptive premise (it tells us what action we should take).
Reason for Fallacy: A prescriptive conclusion can not be derived just from descriptive premises. (Just because something is the way it is isn’t enough for us to act or do something else, there must also be a motivation for oru action)
What is the base rate fallacy?
When people tend to ignore the prevelance or base rate of an occurence across the population
Undistributed middle
- P1 all cats are animals
- P2 all dogs are animals
- C all cats are dogs
Substantive Fallacies
What are Substantive (Informal) Fallacies?
Fallacies that have an inappropriate connection based on a very common but unjustified assumption. Usually there is an implicit premise, which needs to be stated explicitly for the argument to be valid (BUT NOT SOUND)
Substantive Fallacies
What are the different types of Substantive Fallacies?
- Fallacy of Majority Belief
- Common practice
- Gambler’s Fallacy
- Ad Hominem
- Tu Quoque
- Appeal to authority
- Perfectionist Fallacy
- Conflation of morality with legality
- Weak Analogy
- Causal Fallacies
- ~ Post hoc ergo propter hoc
- ~ Mistaking Correlation for cause
- ~ Inversion of cause and effect
- Appeal to ignorance
- Epistemic Fallacy
Substantive Fallacies
What is the Fallacy of Majority Belief?
Concluding that something is true because the majority believes it.
P1) Most people believe the government should lower taxes
C) The government should lower taxes
- Fallacy can be fixed if you add the premise: P2) Any belief shared by most people is true
- Can be a common problem in juries or trials, for example
- Similar to the rhetorical ploy of appeal to popularity, because both use the fact of something’s popularity or commonality to attempt to persuade
- In some cases, such arguments entail both the fallacy of majority belief and the rhetorical ploy of appeal to popularity, in other cases the argument only has one of the two
Substantive Fallacies
What is the Fallacy of Common practice?
When we persuade someone to do something because everyone else does it
P1) Everyone claps at public events
C) It is morally acceptable to clap at public events
- Fallacy can be fixed if you add the premise P2) Any act that everyone performs is morally acceptable
Substantive Fallacies
What is Gambler’s Fallacy?
Assumption that an event occuring frequently or infrequently makes it less likely or more likely respectively to happen again on the next occasion.
P1) I buy five lottery tickets every year
P2) I have never won anything
C) I’m going to buy 5 lottery tickets this year because I haven’t won and now favor’s on my side; it’s my time to win
- Fallacy can be fixed if you add the premises P3) Not winning for a long time means I have better chances of winning and P4) If my chances of winning are increased, it makes sense to buy tickets
Substantive Fallacies
What is the Fallacy of Ad Hominen?
- Responding to someone’s argument by making an attack on that person instead of addressing the argument itself, OR:
- Rejecting a claim because of disapproval/dislike for the perosn who makes it
P1) The prime minister wants to increase taxes
P2) The prime minister doesn’t wear a tie
C) We shouldn’t increase taxes - Fallacy can be fixed if you add the premise P3) Legislation shouldn’t be proposed by someone who doesn’t wear a tie
Fallacy of Ad Hominem
What is the Fallacy of Ad Hominem circumstantial?
When we discount/refute somebody’s argument because the arguer would benefit from that argument (It doesn’t matter if that person will gain or not from his argument, if the reasoning and argument is good, that’s all that matters)
P1) The prime minister wants to increase taxes
P2) The prime minister will benefit from this
C) We shouldn’t allow the prime minister to increase taxes
- Fallacy can be fixed if we add the premise P3) Whenever somebody benefits from something they propose, we should reject their arguments