In the last two lectures we talked about two different kinds of ad hominem arguments. They were silencers and dismissers. In this lecture we're going to talk about the third and final kind of ad hominem argument that we'll be discussing in this course. these are called deniers. So, let's start off with the definitions of deniers. And then, we'll give some examples of deniers that actually are good arguments, followed by some examples of deniers that are fallacies. Okay so first, what's a denier? Well, a denier is a kind of ad hominem argument that begins with premises about a particular person who's making a point, right, that's what makes it an ad hominem, and it ends with a conclusion denying the point that that person is making, denying the conclusion of that persons argument. It's not saying the person isn't authorized or entitled to speak on the issue. It's not saying that the reasons the person presents in favor of their conclusion are somehow defective, false, insufficiently supportive of the conclusion. Rather it's saying, independently of any of that, the conclusion is false. The conclusion that that person is coming to is false. So that's how a denier works. Let me give you some examples of deniers that are actually good arguments. So here's one. Suppose that Arthur performs the following speech act. I, I don't know why Arthur would do this but let's just suppose he does. He says I am an inveterate liar, and most the time I speak falsely, including now. Therefore, this very statement is false. Okay, now, if that's what Arthur says, then we can conclude that the point that Arthur is making, the conclusion that Arthur is drawing from his argument is not true. Alright, because the conclusion that he's drawing from his argument is, this very statement is false. But the problem is, if it's true that this very statement is false, then that means that that statement really is false. In which case, it's not true. So, it can't be true that this very statement is false. In other words, Arthur's conclusion, the conclusion that Arthur reaches at the end of his argument, is not true. Now we just proved that. So, we just proved that by thinking about the performance that Arthur gave where he was making a speech act with that content. He said, I am an inveterate liar, most of the time I speak falsely, even now. Therefore this very statement is false. When Arthur says that we can prove that the conclusion that he's reaching is not true. So there's an example of a denier. It starts with a premise about a particular person, in this case, Arthur, and it's a premise about what Arthur does, and it ends with a conclusion to the effect that the conclusion that Arthur drew is not true. So it denies the conclusion that Arthur drew. So there's an example of a denier ad hominem argument. But that argument actually is a good one. It Arthur issues that particular verbal performance, then the conclusion that he draws is not true. Okay, so there's an example of a denier that's a good argument. Here's another example of a denier that's a good argument. Suppose that Cybil is arguing in front of, let's say, her university's Honor Court, that her classmate Susan cheated on some exam that both Cybil and Susan took. Now I might argue as follows. look into her argument. Cybil did provide a lot of evidence that Susan cheated on the exam. but though Cybil's evidence may seem compelling, in fact Cybil hereself is an unrepentant cheater, who repeatedly tries to hide her tracks. She tries to disguise her cheating planting evidence of cheating on innocent classmates. Therefore, I conclude Cybil's conclusion itself to the effect that Susan cheated, Cybil's conclusion is probably not true. Susan probably did not cheat. Despite the evidence that Cybil has presented against here. Because Cybil does have this track record of planting evidence on innocent classmates. Okay, there also is an example of a denier argument. It starts with a premise about a particular person, in this case Cybil. And, it ends with a conclusion to the effect that Cybil's own conclusion is false, or at least probably false. So, it doesn't say Cibyl isn't authorized to speak on the issue of cheating, it doesn't say that Cibyl's evidence doesn't support her conclusion, it just says that regardless of. Cibyl's entitlement to speak on the issue and the support that her evidence lends to her conclusion. Her conclusion is false, or at least probably false. So that's another example of a denier argument, and there again we have a denier argument that seems like a pretty good argument. It's not deductively valid. But it's a pretty strong argument nonetheless. It's a strong inductive argument nonetheless. Okay, so those are examples of good denier arguments. But we have to search far and wide to find examples of good denier arguments. What we find more often, especially when we look through the media, are examples of bad denier arguments. Denier arguments in which we conclude that someone else's argument leads to a false conclusion, and we draw that conclusion based on features of the person that are really irrelevant to the truth of the conclusion that they're arguing for. We'll see some examples of that right now.
