What makes for a good deductive argument?

A good argument is both
1. Valid
2. Sound

An argument is valid if the conclusion necessarily follows from the truth of the premises.

An example of a valid argument form:

1. If x then y
2. x
3. Therefore, y

Validity doesn’t say whether the premises are true. It only says that the structure of the argument is such a way that IF the premises are true, then the conclusion necessarily follows.

An argument is sound if and only if:
A. The premises are true
B. The argument is valid

An example of a sound argument:
1. All men are mortal
2. I am a man
3. Therefore, I am mortal

Soundness does indeed answer the question of whether the premises are in fact true.

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