Question 1

Suppose you know that an argument is valid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Accepted Answer

No, the conclusion of an valid argument could be true or false. We only know that in either case it will be impossible for it to have all true premises and a false conclusion.

Question 2

Suppose you know that a set is consistent. Can you tell from that whether every set member is actually true? (Defend your answer.)

Accepted Answer

No, a person can have a consistent set of beliefs where one or more are false. If the set is consistent, it only follows that it is possible for every set member to be true.

Question 3

Consider the following argument: 
 1. All men are authors. 
 2. Mark Twain is a man. 
$ / \therefore$ 3.Mark Twain is an author. 
a. Are all of the premises true? 
b. Is the conclusion true or false?
c. Is the argument deductively valid or deductively invalid? 
d. Is the argument sound? Explain, giving the definition of a sound argument.

Accepted Answer

a. No, the first premise is false.
b. True.
c. Valid. 
d. No, since a sound argument is an argument that is valid and has all true premises, but this argument has a false premise.

Question 4

Suppose you know that an argument is sound. What can you determine about its conclusion? (Defend your answer.)

Accepted Answer

If an argument is sound, then it is vali

Question 5

Suppose you know of an argument only that it has all true premises and a true conclusion. Can you tell from that whether it is valid or invalid? (Defend your answer.)

Accepted Answer

No, both valid and invalid arguments can

Question 6

Suppose you know every member of a set of sentences is false. Can you tell from that whether the set is inconsistent? (Defend your answer.)

Accepted Answer

No. You would need t

Question 7

Suppose you know of an argument only that it is valid and has a true conclusion. What, if anything, can you tell about its premises? (Defend your answer, including examples.)

Accepted Answer

You can't tell anything about its premis

Question 8

Suppose you know of an argument only that it is valid and has a false conclusion. What, if anything, can you tell about its premises? (Defend your answer.)

Accepted Answer

At least one of the premises m

Question 9

Consider the following argument:
 1. If George Bush is a Republican, then he is not a Democrat.
 2. George Bush is not a Democrat.
 3. George Bush is a Republican.
 a. Are all of the premises true? 
 b. Is the conclusion true or false?
 c. Is the argument deductively valid or deductively invalid? 
 d. Is the argument sound? Explain, giving the definition of a sound argument.

Accepted Answer

a. Yes.
b. True.
c. Invalid, since it is

Question 10

Suppose you know that argument is invalid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Accepted Answer

No, the conclusion of an inval

Suppose you know that an argument is valid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Suppose you know that a set is consistent. Can you tell from that whether every set member is actually true? (Defend your answer.)

Suppose you know that an argument is sound. What can you determine about its conclusion? (Defend your answer.)

Suppose you know of an argument only that it has all true premises and a true conclusion. Can you tell from that whether it is valid or invalid? (Defend your answer.)

Suppose you know every member of a set of sentences is false. Can you tell from that whether the set is inconsistent? (Defend your answer.)

Suppose you know of an argument only that it is valid and has a true conclusion. What, if anything, can you tell about its premises? (Defend your answer, including examples.)

Suppose you know of an argument only that it is valid and has a false conclusion. What, if anything, can you tell about its premises? (Defend your answer.)

Suppose you know that argument is invalid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Symbolizing in Sentential Logic

Truth Tables

Proofs Without CP or IP

Proofs With CP or IP

Sentential Logic Truth Trees

Predicate Logic Symbolization

Predicate Logic Semantics

Predicate Logic Proofs

Relational Predicate Logic

Quantifier Rules Theory

Predicate Logic Truth Trees

Identity

Syllogistic Logic

Informal Fallacies

Inductive Logic

Axiom Systems

Filters

Exam 1: Introduction

Suppose you know that an argument is valid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Suppose you know that a set is consistent. Can you tell from that whether every set member is actually true? (Defend your answer.)

Suppose you know that an argument is sound. What can you determine about its conclusion? (Defend your answer.)

Suppose you know of an argument only that it has all true premises and a true conclusion. Can you tell from that whether it is valid or invalid? (Defend your answer.)

Suppose you know every member of a set of sentences is false. Can you tell from that whether the set is inconsistent? (Defend your answer.)

Suppose you know of an argument only that it is valid and has a true conclusion. What, if anything, can you tell about its premises? (Defend your answer, including examples.)

Suppose you know of an argument only that it is valid and has a false conclusion. What, if anything, can you tell about its premises? (Defend your answer.)

Suppose you know that argument is invalid. Can you tell from that whether its conclusion is true or false? (Defend your answer.)

Symbolizing in Sentential Logic

Truth Tables

Proofs Without CP or IP

Proofs With CP or IP

Sentential Logic Truth Trees

Predicate Logic Symbolization

Predicate Logic Semantics

Predicate Logic Proofs

Relational Predicate Logic

Quantifier Rules Theory

Predicate Logic Truth Trees

Identity

Syllogistic Logic

Informal Fallacies

Inductive Logic

Axiom Systems

Filters