Comments Elsewhere

Thanks to Roderick Tracy Long for the example. Here’s an argument. I maintain that it is deductively valid, and so if all of its premises are true, then the conclusion must be true. 1. This argument is a valid argument. (Pr.) 2. This argument has all true premises. (Pr.) 3. The conclusion of this argument is: “Mitt Romney actually won the election, and is now President of the United States.” (Pr.) 4. If an argument is a valid argument and has all true premises, then the argument is sound. (Pr.) 5. All sound arguments have true conclusions. (Pr.) 6. If the sentence “Mitt Romney actually won the election, and is now President of the United States” is true, then Mitt Romney actually won the election, and is now President of the United States. (Pr.) 7. This argument is a valid argument and this argument has all true premises. (Conj. 1,2) 8. This argument is a sound argument. (MP 4, 7) 9. If this argument is a sound argument, this argument has a true conclusion. (UI 5, 9) 10. This argument has a true conclusion. (MP 9, 8) 11. The sentence “Mitt Romney actually won the election, and is now President of the United States” is true. (Subst. 10, 3) 12. Mitt Romney actually won the election, and is now President of the United States. (MP 6, 11) QED. If the argument is sound, then the conclusion has to be true. If the argument is deductively valid, but the conclusion is not true, then at least one of the premises has to be false. But which premise is the false premise? And why is it false?