Introduction: What is an argument?
Thursday, 6 August 2020
12:00
Reading:
These two items will give you an accessible introduction to some of the concepts and
notions that we will be dealing with throughout the course. They are recommended
reading:
* Merrilee H. Salmon, Introduction to Logic and Critical Thinking (sixth edition,
Wadsworth 2012), Chapter 1 (pages 1-46) [Available on the course’s LEARN
webpage]
* A. W. Sparkes, Talking Philosophy: A Wordbook (Routledge 1991), Sections 4.1 to
4.8 (pages 75-84) [Available on the course’s LEARN webpage]
* Luís Duarte d’Almeida, “What is an Argument?” (unpublished typescript, written
specifically for Critical Legal Thinking students) [Available on the course’s LEARN
webpage]
The following items may also be useful:
Elias E. Savellos, Reasoning and the Law: The Elements (Wadsworth 2001)
Sections 2.1 and 2.2 (pages 23-30) [Available on the course’s LEARN webpage]
Bruce N. Waller, Critical Thinking: Consider the Verdict (sixth edition, Pearson 2012),
Chapter 2 (pages 14-27) and Chapter 5 (pages 68- 75) [On reserve at the Law
Library]
Walter Sinnott-Armstrong and Robert Fogelin, Understanding Arguments: An
Introduction to Informal Logic (ninth edition, Cengage Learning 2015), Chapter 1
(pages 3-15) and Chapter 3 (pages 41-57) [On reserve at the Law Library]
Notes
1. Introduction
Should prisoners be allowed to vote?
Yes, May risk democracy
No, Imprisonment designed to curtail certain civil liberties
1.1
If ___, then ___
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote CONDITIONAL SENTENCE
1.2
If ___, then ___
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote ANTECEDENT
1.3
If ___, then ___
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote CONSEQUENT
1.4
If ___, then ___
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote
p = criminal sanctions should aim at the rehabilitation of offenders
1.5
If ___, then ___
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote p = criminal sanctions should aim at the
rehabilitation of
offenders
q = prisoners should be allowed to vote
,1.6
If p, then q
If criminal sanctions should aim at the rehabilitation of
offenders, then prisoners should be allowed to vote p = criminal sanctions should aim at the
rehabilitation of
offenders
q = prisoners should be allowed to vote
1.7
1. (1) If p, then q
2. (2) p
Therefore (from (1) and (2)),
(3) q
1. (1) If p, then q
2. (2) p
Therefore (from (1) and (2)), (3) q
(premise) (premise)
(conclusion)
1.8
• Premise (1) will be a conditional sentence
• Premise (2) will affirm the antecedent of premise (1) • The conclusion will be the consequent of
premise (1)
Take a minute
2. What is an argument?
1. (1) If p, then q (premise)
2. (2) p (premise)
Therefore (from (1) and (2)),
3. (3) q (conclusion)
• This is not an argument: it is the form of an argument
• In any argument of this form, the conclusion follows from the premises: what this means is
that if the premises are both true, the conclusion cannot be false.
• That is what we call a valid argument.
• (There are many other forms of valid argument.)
2.1
But a valid argument is not necessarily a good one: we also want the premises to actually be true.
Consider:
(1) If today is Friday, then prisoners should be allowed to vote.
(2) Today is Friday.
Therefore (from (1) and (2)),
(3) Prisoners should be allowed to vote.
2.2
But a valid argument is not necessarily a good one: we also want the premises to actually be true.
Consider:
(1) If today is Friday, then prisoners should be allowed to vote.
(2) Today is Friday.
Therefore (from (1) and (2)),
(3) Prisoners should be allowed to vote.
This is a valid argument but doesn’t mean that the premises are true so not a sound argument as the
premises has no correlation to the conclusion (the antecedent to the consequent).
Summing up (1/2)
• An argument is a group of claims arranged in a particular way.
• A group of claims is arranged as an argument when (a) one of the claims (called the
“conclusion”) is treated as controversial (that is, as a claim to be demonstrated, argued
for), and (b) the other claim(s) (called the “premise(s)”) are put forth as claims meant to
establish the conclusion.
Summing up (2/2)
, • An argument is valid when the conclusion follows from the premises (in other words,
when the premises imply the conclusion). That means that it is not possible for the
conclusion to be false if the premises are all true.
• A valid argument can have false premises and a true conclusion, or even false premises and
a false conclusion.
• The only thing a valid argument cannot have is true premises and a false conclusion.
• A valid argument is sound when all the premises are actually true.
This course
• This is a course about arguing, reasoning, and thinking critically about law
• Wednesday lectures will be dedicated to collectively discussing practical examples: you
should read the materials in advance of each lectures
• Six tutorials (weeks 3, 5, 6, 8, 10, and 11)
• One final exam with two components
• One optional formative assessment in week 7 (worth 5 bonus marks for students who get
every question right)
• Class representative: to be chosen next Wednesday
Lecture 2.
Wednesday, 13 January 2021
12:05
Before we start
Remember what we’ve seen on Monday:
• An argument is a group of claims arranged in a particular way.
• A group of claims is arranged as an argument when (a) one of the claims
(called the “conclusion”) is treated as controversial (that is, as a claim to be
demonstrated, argued for), and (b) the other claim(s) (called the
“premise(s)”) are put forth as claims meant to establish the conclusion.
Exercise W1.1
“[T]he outcome of litigation should be final. Where an issue has been determined by a
decision of the court, that decision should definitively determine the issue as between
those who were party to the litigation. Furthermore, parties who are involved in litigation
are expected to put before the court all issues relevant to that litigation. If they do not, they
will not normally be permitted to have a second bite at the cherry.”
How many arguments can you spot in this passage?
— “[T]he outcome of litigation should be final.” — “Why?”
— “Where an issue has been determined by a decision of the court, that decision should
definitively determine the issue as between those who were party to the litigation.”
• The “Why?” question here is a demand that the arguer show that the claim is true: it is a
request for reasons that show that we should indeed accept the claim as true. That is what
giving an argument involves. This is e "Why?" of Argumentation.
“[T]he outcome of litigation should be final. Where an issue has been determined by a
decision of the court, that decision should definitively determine the issue as between
those who were party to the litigation. Furthermore, parties who are involved in litigation
are expected to put before the court all issues relevant to that litigation. If they do not, they
will not normally be permitted to have a second bite at the cherry.”
How many arguments can you spot in this part of the passage?
• Here (third and fourth sentences) the Court could perhaps be understood to
be offering an explanation of why it is that (as a matter of law) parties
involved in litigation are not normally “permitted to have a second bite at
the cherry.”
• But this is a different sort of “Why?”
, • It is the “why” of explanation, not the “why” of
argumentation.
• The difference is not immediately obvious, but it is an important one.
• An explanation assumes that something (the “explanandum”, that which is
to be explained) is true, and specifies its causes; it purports to show why it
is true.
• Example: “The reason that Parliament passed this law is that it wanted to
give effect to an EU directive.”
• An argument, by contrast, does not assume that the conclusion is true:
rather, it treats the conclusion as a controversial claim, and purports to
demonstrate that it is indeed true.
• So when we say “Why?” to ask for an argument, what our question means is
(roughly) “Why should I agree with you that that claim is indeed true?”
Question: How many arguments can you spot in this passage?
There are two arguments.
No, there are no arguments.
One:
Where an issue has been determined by a decision of the court, that decision should
definitively determine the issue as between those who were party to the litigation.
[T]he outcome of litigation should be final.
Two:
Furthermore, parties who are involved in litigation are expected to put before the court all
issues relevant to that litigation. If they do not, they will not normally be permitted to have a
second bite at the cherry.
• Conditional sentence is not enough to have an argument, AN ARGUMENT IS
A GROUP OF CLAIMS (At least two)
• Don’t repeat premises in conclusion when making an argument. Make
different premesis that lead to the same conclusion to PERSUADE.
Exercise W1.2
“If [the defendant] wished to deal with his assets he had to obtain the permission of the
court. Since he failed to do so it follows that he has acted in breach of the Freezing Order.”
This is clearly an argument. How can we tell?
We can tell that there is an argument from the use of words such as "since" (reason) and
"it follows" (conclusion). "It follows" is a strong indicator that there is an argument. Not
conclusive indicator of argument.
When reconstructing an argument, always start with the conclusion.
If [the defendant] wished to deal with his assets he had to obtain the
permission of the court. Since he failed to do so it follows that he has acted in
breach of the Freezing Order.
Questions: Identify the conclusion and the premises of the argument
just quoted. Does it look valid? How would you reconstruct it?
• If the defendant wished to deal with his assets, then he had to
obtain the permission of the court, then the defendant acted in
breach of the Freezing order.
