quiz 7 Flashcards
Until this chapter, what kind of syllogisms have we been studying?
Categorical Syllogisms
Upon what does the validity of categorical syllogisms depend?
Upon the relationships among the terms in the syllogism
Upon what does the validity of hypothetical syllogisms depend?
Upon the relationship among the propositions in the syllogism
In what way is the word term used differently in hypothetical reasoning than in categorical reasoning?
We are referring to the whole propositions that we represent by the letters P, Q, etc.
In what way are the phrases major premise and minor premise used differently in the context of hypothetical
syllogisms than in the context of categorical syllogisms?
They are used for convenience. The first statement (if P, then Q) is the major premise. The second statement is the minor.
How is the major premise in a conditional syllogism constructed?
The major premise is a conditional statement (If . . . then).
How is the minor premise constructed?
The minor premise is a conditional statement affirming or denying an element of the major premise.
How is the minor premise constructed?
The minor premise is a conditional statement affirming or denying an element of the major premise.
Define the terms antecedent and consequent
Antecendent is the part that comes after the “if”. The Consequent is the part that comes after the “then” in a conditional statement.
What is the meaning of modus ponens, and why is it an appropriate label for the first valid mood?
Latin for “affirmative mood”, which means the antecendent is of the major premise is affirmed, thereby affirming the consequent.
What is the meaning of modus tollens, and why is it an appropriate label for the second valid mood?
Latin for “mood of denial”, which denies the consequent and thereby denying the antecedent.
Give the form of a modus ponens syllogism (use the letters P and Q).
If P, then Q. P. Therefore, Q
Give the form of a modus tollens syllogism (use the letters P and Q).
If P, then Q. Not Q. Therefore, not P.
Explain the Fallacy of Affirming the Consequent,
It means we are saying that the consequent is true. But just because the consequent is true, it doesn’t follow that the antecedent is.
Explain the Fallacy of Denying the Antecedent.
Just because the antecedent is false, it doesn’t follow that the consequent is false.
