Question

Explain the difference between a valid argument and a sound argument, and give an example of each.

Answer 1

An argument is valid if true premises always leads to true conclusions. An argument is sound if and only if it is valid and all of the premises are true.

Consider the following two arguments.

Premise 1: Socrates is a man.
Premise 2: All men are green.

Conclusion: Socrates is green.

Premise 1: Socrates is a man.
Premise 2: All men are mortal.

Conclusion: Therefore, Socrates is mortal.

Both argument share the form:

A is B.
All B are C.
Therefore, A is C.

All arguments with this form are valid. Hence, both of the example arguments are valid. However, the first example is unsound because the second premise is false, while the second example is sound because both of its premises are true.

A valid argument is an argument that has strong points but may leave some holes in it that can be easily found or exploited. But is stills proves a stance.

A sound argument is much harder to find holes in, it still proves a point, but it uses information that can be hard to loop or exploit. Or it has very strong information and statistics in it that can not be refuted.

An argument is valid if the conclusion necessarily follows the premises, regardless of the veracity of these premises.

That should be the same thing. A valid argument is a sound one. You could use both and it wouldn’t do anything.

A “valid”deductive argument is such that provided the premises are true there is no way the conclusion can be false. A “sound” deductive argument is both valid and has true premises.

An argument is valid if and only if

1. The truth of its premises entails the truth of its conclusion.

2. Each step, sub-argument, or logical operation in the argument is valid.

An argument is sound if and only if

1. The argument is valid.

2. All of its premises are true.

example of valid argument

an argument is valid if the truth of the premises logically guarantees the truth of the conclusion. The following argument is valid, because it is impossible for the premises to be true and the conclusion nevertheless to be false: Elizabeth owns either a Honda or a Saturn. Elizabeth does not own a Honda.

example of sound argument

A sound argument is one that is not only valid, but begins with premises that are actually true. The example given about toasters is valid, but not sound. However, the following argument is both valid and sound: In some states, no felons are eligible voters, that is, eligible to vote.