Repairing Arguments

There are three guidelines required in repairing an argument in order to make it better. If the argument is bad, we are justified in adding a premise or conclusion that satisfies these three guidelines.
1. The argument becomes stronger or valid.
2. The premise is plausible and would seem plausible to the other person.
3. The premise is more plausible than the conclusion.

Example: “All models are tall; Sally is tall, therefore, Sally must be a model”

Analysis: “Sally is a model” is the only premise that will make this valid or strong argument. Saying Sally is a model is the only premise plausible enough for the other person to understand the argument. This is when you say an assumption works in both directions, even if there’s no reason to believe so. Just because A means B doesn’t mean B means A. The sentence is also a good indicator of a conclusion because it uses the word, “therefore” which shows that a conclusion is coming up.