Introduction to Logic

Study Questions

An argument is valid if and only if it is impossible for all its premises to be true and its conclusion false.

A valid argument preserves truth:
1. when all premises are true, the conclusion is also true.
2. when the conclusion is false, at least one premise must be false.

An argument is invalid if and only if it is possible for all its premises to be true and its conclusion false.

1. Given a valid argument with a false conclusion, what, if anything, does one know about the truth or falsity of its premises?
True False Undetermined

2. Given an invalid argument with a true conclusion, what, if anything, does one know about the truth or falsity of its premises?
True False Undetermined

3. Given a valid argument with all false premises, what if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

4. Given an invalid argument with all false premises, what if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

5. Given a valid argument with all true premises, what if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

6. Given an invalid argument with all true premises, what if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

7. Given a valid argument with all true premises, what if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

8. Given an invalid argument with a false conclusion, what, if anything, does one know about the truth or falsity of its premises?
True False Undetermined

9. Given a valid argument, what, if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

10. Given an invalid argument, what, if anything, does one know about the truth or falsity of its conclusion?
True False Undetermined

11. Given a valid argument with a true conclusion, what, if anything, does one know about the truth or falsity of its premises?
True False Undetermined