Logic Practice Exam

False

All arguments with a false premise are uncogent

What is a Valid Argument?

An argument in which it is necessary that, if the premises are true, then the conclusion is true

What is an invalid argument?

An argument in which it is not necessary that, if the premises are true, then the conclusion is true.

What is a weak argument?

An argument in which it is not probable that, if the premises are true, then the conclusion is true

What is a strong argument?

An argument in which it is probable (but not necessary) that, if the premises are true, then the conclusion is true.

What is an unsound argument?

An argument that is either invalid or has a false premise

What is an Uncogent Argument?

An argument that is either strong with at least one false premise or weak

True

If an argument has one false premise, then it is unsound

If you want to ruin your life, you should take hard drugs. But you don't want to ruin your life. So, you should not take hard drugs.

Invalid (denying the antecedent)

Philosophy is important if ideas are important. And assuming that ideas change lives, ideas are important. So, if philosophy is important, then ideas change lives.

Invalid (unnamed invalid form)

False

Some arguments have valid premises, and some do not

False

Some sound arguments have a false conclusion

False

Some statements are invalid

What is Inductive Logic?

The part of logic concerned with the study of methods of evaluating arguments for strength and weakness

What is deductive logic?

The part of logic concerned with the study of methods of evaluating arguments for validity and invalidity

Either the "eye for an eye" principle is interpreted literally or it is interpreted figuratively. If it is interpreted literally, then the state should torture torturers, maim maimers, and rape rapists. If the "eye for an eye" principle is interpreted figuratively, then it does not necessarily demand death for murders. So either the state should torture torture, main maimers, and rape rapists, or the "eye for an eye" principal does not necessarily demand death for murderers.

Valid (constructive dilemma)

If the zygote lacks a brain, then the zygote lacks a soul. If the zygote lacks a soul, then killing the zygote is permissible. So, if the zygote lacks a brain, then killing the zygote is permissible.

Valid (hypothetical syllogism)

Overeating is foolish only if it causes disease. Overeating does not cause disease. So, overeating is not foolish.

Valid (modus tollens)