Rather, here, what it is to[br]say that a reason is good is closely tied to the notion of truth.
So a good reason for a belief is one that makes it probable, that is, it's one that makes the belief likely to be true.
So, for example, if you found out that your friend was[br]the person who decided who was going to be invited to the party, then the fact that she can't stand Monty and wants to have a good time would give you a good reason to believe that Monty won't be at the party, because it would give you reason to believe that she didn't invite him. Those two premises[br]considered in themselves give you no reason to believe that Monty won't be at the party.
Okay, our last topic is to distinguish two different types of arguments.
We're gonna talk about three possible answers she could give.
First, she might say, "I can't stand him, and I want to have a good time." Second, she might say,[br]"Well, he's really shy, and he rarely goes to parties." And third, she might say, "He's in Beijing, and it's impossible to get here from[br]Beijing in an afternoon." The first response that she gives you does not give you a good reason to believe that Monty won't be at the party.Similarly, the third reason[br]also gives you a good reason to believe that[br]Monty won't be at the party.If he's in Beijing, and[br]it's impossible to get here from Beijing in an afternoon,[br]then it's guaranteed that he won't be at the party.In this lesson, we're gonna[br]talk about three things. And she says to you, quite confidently, "Monty won't be at the party." You're not sure whether[br]or not to believe her, so it would be natural[br]for you to follow up by asking, "Why do you think so?" And there are a lot of different things that she might say in response.The second reason,[br]though, is a good reason to believe that Monty[br]won't be at the party.If he's really shy and[br]rarely goes to parties, then it's probable that he[br]won't be at tonight's party.So "Monty's really shy" is premise one, "Monty rarely goes to[br]parties" is premise two, and the statement that[br]those premises give you reason to believe, we call[br]the argument's conclusion.A good argument is one[br]in which the premises give you a good reason for[br]the conclusion, that is, the premises make the[br]conclusion likely to be true.Now, it's worth saying something about how I'm using the term "good" here.I'm not using it to indicate anything having to do with morality or ethics.