Informal Fallacies

Question 1

In what way are informal fallacies flawed?

Answer 1

• they are valid arguments
• flawed due to
  (a) pointlessness of the argument
  (b) irrelevance of the conclusion
  (c) in some cases, falsehood of a premise

Question 2

Give an example of a ‘begging the question’ argument

Answer 2

(1) The contract between the claimant and the defendant was validly concluded
(2) The contract between the claimant and the defendant was validly concluded

Question 3

Why are begging the question arguments fallacious?

Answer 3

as they go against the very point of giving arguments (premises) in support of conclusions

Question 4

What is the technical fault with begging the question arguments?

Answer 4

that they assume what you must prove

Question 5

Give the three alternative names for a question begging argument

Answer 5

• circular argument
• bootstrapping argument
• petitio principii

Question 6

Question begging arguments are often hidden, give an example of this

Answer 6

Quinn v Leathem (1901)

Question 7

What is the straw man fallacy?

Answer 7

it is the fallacy of engaging with - and arguing against - an argument that is not really being endorsed by the other party in the debate, purporting to have thereby refuted the other party’s actual argument

Question 8

Give a case example where a straw man fallacy arises

Answer 8

Astle v CBRE (2015)

Question 9

What second fallacy is committed when using a straw man argument?

Answer 9

Irrelevant conclusion

• any argument for a conclusion that is irrelevant for what is being debated commits a fallacy of relevance
• otherwise known as ignoratio elenchi

Question 10

What is an exhaustive disjunction?

Answer 10

one that leaves no room for another possibility

‘the football team either won, lost or tied’

Question 11

What is a non-exhaustive disjunction?

Answer 11

leaves room for other possibilities

‘the football team won or lost’

Question 12

What does the fallacy of false dichotomy rely on?

Answer 12

disjunctions

Question 13

Give the valid form of disjunctive syllogism

Answer 13

(1) P or q
(2) Not p
(3) Q

Question 14

An arguer who offers a disjunction syllogism will be asserting the relevant disjunctions as exhaustive, give an example of this

Answer 14

(1) The plantiff was unlawfully dismissed or the plantiff was lying about what happened
(2) It is not the case that the plantiff was unlawfully dismissed
(3) The plantiff was lying about what happened

Question 15

Why is false dichotomy fallacious

Answer 15

• relies on a disjunction (which the arguer takes to be exhaustive) that is actually false
• as it rules out other relevant possibilities

Question 16

Define the term ‘tertium quid’

Answer 16

a third thing that is indefinite and undefined but is related to two definite or known things

(there is a…)

Question 17

In the legal sense, what does a false dichotomy refer to?

Answer 17

(a) the informal fallacy of relying on a disjunction that is wrongly taken to be exhaustive
(b) the formal fallacy of affirming a disjunct

Question 18

What is a fallacy fallacy?

Answer 18

it is a fallacy to infer, from the fact that a certain argument is fallacious, that its conclusion must be false

Question 19

Give an example of the fallacy fallacy

Answer 19

(a non sequitur argument)

(1) Argument X is fallacious
(2) The conclusion of argument X is false

• the only thing that follows from (1) is that the proponent of argument X failed to establish its conclusion
• but that does not mean that the conclusion is actually false

Question 20

Name the four informal fallacies and give a summary of each

Answer 20

• begging the question
  (assuming what you need to prove
• straw man
  (refuting a weaker version of someone’s argument and purporting to have thereby refuted their actual argument
• irrelevant conclusion
  (presenting an argument for a conclusion whose truth is immaterial for what is at issue)
• false dichotomy
  (relying on a disjunction that you take to be exhaustive when there are other possibilities that you should’ve taken into account