Is the argument "I love all logic, but I don’t love deductive reasoning. Therefore, the moon is made of green cheese." valid?

Answer 1

No, this argument is not valid.

Validity refers to the logical structure of an argument. It does not refer to the content.

For example:

This is valid

All men are mortal

Socrates is a man

Therefore, Socrates is mortal

This is also valid

All men are plants

Socrates in a man

Therefore, Socrates is a plant

Now, although both are valid, both are not sound. "Soundness" means that the argument is valid and the premises are true. Since the premises in the second argument are not true, the argument is unsound.

The argument you've given is neither valid nor sound. Also, if we look at the content, it is a non sequitur: the fact that you love or hate something has no relationship to the truth of something else. For example, I don't like onions therefore onions are poisonous to human beings. My conclusion doesn't follow. Just because I don't like onions does not mean that they are poisonous. Just because the above premise states that someone doesn't love deductive reasoning has no bearing on what the moon is made of.