Legal Syllogism

Question 1

Consider this argument

(1) Every reasonable person would have foreseen that the act would in all probability injure someone else
(1*) If the accused is a reasonable person, then the accused would have foreseen that the act would in all probability injure someone else

What are the differences between each of the claims?

Answer 1

(1*) - is about a particular individual (the accused)

(1) - is about any individual who can be said to be a reasonable person
- known as a universal sentence
- it asserts that every member of the class of reasonable persons is a member of the class of people who would have foreseen that the act would in all probability injure someone else

Question 2

Consider this argument

(1) Every reasonable person would have foreseen that the act would in all probability injure someone else
(1*) If the accused is a reasonable person, then the accused would have foreseen that the act would in all probability injure someone else

Are both of these claims conditional?

Answer 2

(1*) - is a complex conditional sentence (p and q)

(1) - is not a complex conditional sentence
- the sentence states that it is true of every individual that if they are a reasonable person, then they would have foreseen the act…

Question 3

(1) Every reasonable person would have foreseen that the act would in all probability injure someone else

What is the underlying structure of this premise?

Answer 3

for every x = if x is a reasonable person, then x would have foreseen that the act would in all probability injure someone else

Question 4

For every x = if x is a reasonable person, then x would have foreseen that the act would in all probability injure someone else

What does the letter ‘x’ stand for in this?

Answer 4

• unlike ‘p’ and ‘q’, the letter ‘x’ does not stand for a complete sentence in english
• ‘x’ stands for any individual that meets the relevant description
• ‘x’ is known as an individual variable
• ‘x’ does not stand for any individual in particular

Question 5

Give the basic structure of a universal modus ponens argument

Answer 5

(1) For every x, if x P, then x Q
(2) x P
(3) x Q

Question 6

Where does the difference occur between modus ponens and universal modus ponens?

Answer 6

in premise (1)

Question 7

Give the basic structure of universal modus tollens

Answer 7

(1) For every x, if x P, then x Q
(2) It is not the case that, x Q
(3) It is not the case that, x P

Question 8

Give the basic structure of universal denying the antecedent

Answer 8

(1) For every x, if x P, then x Q
(2) It is not the case that, x P
(3) It is not the case that, x Q

Question 9

Why are universal sentences important?

Answer 9

the standard form of a statement of a legal rule = a universal sentence

Question 10

Name the three components that make up a legal syllogism

Answer 10

• one legal premise (major)
• one factual premise (minor)
• the conclusion which is also a legal statement

Question 11

As they are both legal statements, what is the difference between the major premise and the conclusion of a legal syllogism?

Answer 11

• the major premise = general statement of law

- the conclusion = particular statement of law

Question 12

How is a valid legal syllogism justified?

Answer 12

Internally

Question 13

What is meant by internal justification?

Answer 13

concerns the relations between the premises and conclusion

Question 14

How is a sound legal syllogism justified?

Answer 14

Externally

Question 15

What is meant by external justification?

Answer 15

• the external justification of the factual premise will require non-deductive reasoning about the evidence presented by the parties
• the external justification of the legal premise will require giving reasons of different important sorts

Question 16

What is meant by the order of justification?

Answer 16

the structure of a valid legal syllogism shows the conclusion to follow from the premises (which are logically prior)