I've been taking this Philosophy courses at my college and I got stuck at these homework. It asks to identify in the given paragraph which arguments is sound or unsound, and if it is unsound, I have to correct it to make it sound. Now, I know all the basic concept and definition. In order for an argument to be sound, it need to be valid first, and all the premises have to be true also. However, I come across a lot of premises that are not fact, meaning they are not verifiable. If that's the case, how do I know that it's a sound or unsound argument ? Here are some arguments that I come across:
1. If I had ADD, I'd have a prescription for this drug. But I don't have a prescription, so it's clear I don't have ADD. A = I had ADD B = I have a prescription The symbolic form is: If A then B ~B --------------- ~A 2. I haven't studied at all. If I don't study all night, I'll fail the test. But I can't fail the test, so I must study all night. A = I don't study all night B = I'll fail the test. If A then B ~B ------------ ~A
Both of them are valid arguments. However, I can't tell if they are sound or unsound, since all the premises are not facts, they're just some assumptions and all. How can I tell if they're sound or not ? And if they're unsound, what would I should add in to the premises to make the the argument become sound ? Thank you.