PRESENTER: Since arguments are at the heart of logic and argumentation, it's natural to start with this question. The first thing to say about arguments is that as this term is used in logic, it isn't intended to imply anything like an emotional confrontation, like when I say that an argument broke out at a bar, or I just had a huge argument with my parents about my grades or something. In logic, an argument is a technical term. It doesn't carry any connotation about conflict or confrontation. 

So here's our definition. It'll have three parts. First part; an argument is a set of claims or statements. We'll have more to say about what a claim or statement is later, but for now, it's enough to say that a claim is the sort of thing that can be true or false. 

Next part; one of the claims is singled out for special attention. We call it the conclusion. The remaining claims are called the premises. And finally, the premises are interpreted as offering reasons to believe or accept the conclusion. That's it. That's the definition of an argument. 

Now, let's have a look at one. All musicians can read music. John is a musician, therefore John can read music. These are the premises, and this is the conclusion. 

Premises one and two are being offered as reason to accept the conclusion that John can read music. This may not be a particularly good argument, actually, since that first premise makes a pretty broad generalization about all musicians that isn't very plausible, I don't think. I'm sure there are a few great musicians out there that don't read sheet music, but it's an argument nonetheless. 

Now, notice how it's been written. The premises are each numbered and put on separate lines, and the conclusion is placed at the bottom and set off from the rest by a line and flagged with the word therefore. This is called putting an argument in standard form. And it can be useful when you're doing argument analysis. 

In ordinary language, we almost never are this formal. But when you're trying to analyze arguments, when you're investigating their logical properties, or considering whether the premises are true or not, putting an argument in standard form can make life a lot easier. 

Now, just to highlight this point, here's another way of saying the same thing. Can John read music? Of course! He's a musician, isn't he? Now, these actually express the very same argument. But notice how much easier it is to see the structure of the argument when it's written in standard form. 

In the second version in yellow here, you have to infer the conclusion. John can read music from the opening question and the "of course" part. And you have to fill in an assumed premise. What you're given is "John is a musician," but the conclusion only follows if you assume that all musicians, or most musicians, can read music, which is not a given. It's just a background assumption. 

The argument only makes sense because you're filling in the background premise automatically. But you can imagine that this might become a problem for more complex arguments, where you can't always be sure that everyone is filling in the same background premise. So the standard form can be helpful, and we're going to be using it a lot in this course. 

Here are the takeaway points to remember from this. First, an argument is just a set of claims that are offered as reasons to believe or accept another claim. Second, we saw that the same argument can be written in more than one way. And in general, it's true that the same argument can be written or expressed in many different ways, using different words, different sentences, and different sentence structure. 

Now, because of this, it's often helpful to put arguments in standard form, where you can clearly identify which parts of the argument are functioning as the premises and which part is the conclusion. And you make all the premises and background assumptions explicit by writing them on separate lines. And being able to do this is actually an important skill in logic.