Logic: Deductive Validity

Question 1

What steps should be taken when assessing arguments (2)

Answer 1

1. Asking whether the conclusion would neccessarily be true if the premises were true (validity)
2. Check if the premises are in fact true (soundness)

Question 2

What could be the case if the first steo in assessing arguments is not satisfied?

Answer 2

Ask is the conclusion likely to be true assuming all premises are true. If the answer is no,
then the argument is invalid and non-forceful. If the
answer is yes, the next question becomes whether
the premises are in fact true. If the answer to this
question is no, then the argument is forceful but
unsound. If the answer to this question is yes, then the argument is forceful and sound.

Question 3

When is an argument inductively forceful?

Answer 3

An argument is inductively forceful if the conclusion is more likely to be true than false. More likely means P>0.5).

Question 4

What kind of diagram can be constructed to assess the validity of arguments?

Answer 4

Venn diagram

Question 5

What does the principle of charity state?

Answer 5

the best possible reconstruction of an argument should be used.

Question 6

Give 6 equivalents to “If A then B”

Answer 6

• B, if A
• If not B, then not A
• Not A if not B
• A, only if B
• Not A, unless B
• B or not A

The word unless is equivalent to if not.