We've devoted this week so far to talking about fallacies or relevance but today we're going to talk about fallacies of vacuity. Let me begin by defining what a fallacy of vacuity is. A fallacy of vacuity is a fallacy that results. When, roughly speaking, an argument starts by assuming what it's supposed to establish. You could think of it this way. A fallacy of vacuity is an argument that doesn't go anywhere. its starting points presuppose what it is that the argument is supposed to prove. Okay, so there are different kinds of fallacies of vacuity. And in this lecture and the next we are going to be talking about three different kinds of fallacies of vacuity. The first is something called circularity. A circular argument. A fallacy of circularity occurs when, an argument's conclusion is contained among its premises. Eh, you write out the premises of the argument and one of the premises just is the conclusion, that's a circular argument. And that fallacy is called circularity. another broader kind of fallacy of vacuity when I say broader kind of fallacy of vacuity. I mean this kind of fallacy of vacuity includes circularity as a sub species is what's called begging the question. Begging the question is when an argument has the following feature. In order to be reasonable in believing the premises of that argument, you already have to have a good reason for believing the conclusion. So, unless you already have a good reason for believing the conclusion independently of the premises. The argument can't go anywhere because you won't have a good reason for believing the premises. And so, if you don't have a good reason for believing the premises, then the argument can't give you a good reason for believing the conclusion. So roughly, an argument begs the question when you need to have a good reason for believing the conclusion already in order for you to have an reason to believe the premises of the argument. That's begging the question, right? That includes circularity. Because notice, in a circular argument, you have to have a good reason for believing the conclusion in order to have a good reason for believing the premises. Because the conclusion is one of the premises. But begging the question can happen even without circularity, and we'll talk about examples of that next time. The last kind of fallacy of vacuity that I wanted to describe is something called self-sealing. Now a self-sealer can be either a proposition or an argument. But roughly, a self-sealer is when a proposition or an argument is irrefutable by any possible consideration, no matter what. And so it doesn't rule out anything. So, if I make some claim to the effect that at a certain point in time, you will then be doing exactly what you will be doing. You might think, well yeah, so what does that tell me? What possible situations are ruled out by that statement? The answer is none. And so that statement is empty, it's vacuious. It's a self-sealer in the sense that there's no possible situation that it rules out. And so there's no possible consideration or evidence that could be brought forth against it. A self-sealing argument is one that commits a fallacy of acuity. Because it does assume what it's intended to establish. Unfortunately, in a self-sealing argument. What it's intended to establish is nothing of any significance. It's nothing that rules out any possibility. And so, it does tend to assume what it's supposed to establish. So, those are three kinds of vacuity that I wanted to distinguish. In the next lecture, we'll talk a bit more about circularity and begging the question. And in the lecture after that, we'll talk a bit more about self sealing. See you next time.