Sometimes, I like to think about how things are labeled as true or false and good or bad. It is very easy to decide whether statements are true. I could say that I am wearing a blue sweater, for example, and this statement would be true or false in the world that we are in. Since I am not wearing a blue sweatshirt, this sentence would be false. It is much harder to define what it means for an argument to be good. If I say: “All bananas are yellow. I am holding a banana. Therefore, I am holding a yellow banana,” intuitively, you would call this a good argument, but why? Is it because we know that it is, indeed, true that if I were holding a banana it would be yellow? If this were the way in which we define whether an argument is good, we could run into some problems. Consider the following argument: “All bananas are blue. Therefore, all bananas are yellow.” Here, our conclusion is true in our world, but it’s hard to say that the argument is a good one. Thus, I like to evaluate a...