![]() ![]() Validity is a relationship between the first set of sentences and the conclusion. An argument is valid, logicians say, when we have one set of statements which we call the premises and if they are true, then this other statement, the conclusion, must be true. One of the key concepts in formal logic is the concept of validity. It’s a very particular conception of argument that we’ve appealed to here: the idea that we’re moving from some truths to some more truths. That relationship between sets of statements is the primary interest. ![]() We’ve taken a set of statements which are agreed to be true, and then we’ve worked out which other statements we have to accept if we’ve accepted those ones as true. For example, when I give an argument, I start with some claims upon which we both agree, and eventually we get to a point where you accept something that you didn’t previously accept on the basis of those claims we’ve started by agreeing on. Why do logicians want to study that? The reason is often best explained in terms of arguments. If we take the group of speech acts of asserting truths – ‘making a statement’ is often the favoured phrase – the question is what are the relationships between these different statements? That’s what logicians study. Logic is not concerned with which sentences are true it’s concerned with the patterns of truth. It’s interesting you’re talking about truth, because that makes it sound a bit like epistemology-as in, how do we know that things are true? But logic is usually not thought of as a branch of epistemology. That’s pretty much definitional of this conception of formal logic. In other words, when speakers of different languages are engaged in talking about what’s true or what’s false and have no other interests, then languages are perfectly inter-translatable. It’s a working assumption of this approach that when we make it explicit for one language, we could do the same thing for any other language. So let’s take those bits of the language where we’re concerned with truth and falsity and the relationships between truths, and see if we can make those properties explicit. They may have lots of other things they do as well, but an interest in truth is common to all of them and it’s clearly very important. The most common conception of formal logic is that it’s saying all languages have this interest in truth. If we think one thing is true, then we may be committed to thinking something else is true. They also allow us to make connections between different truths we speak about. One of the things that all languages do is allow us to speak truly or falsely. The first and most common-the one used in universities when teaching formal logic-is to think of it as a particular kind of study of the very general properties of languages that is, natural languages, the languages which we all speak and write. There are two ways of understanding formal logic which are subtly and importantly different. Foreign Policy & International Relationsīefore we get to the books, can I begin by asking the most obvious question, which is what is logic?Ī bit like ‘philosophy’, ‘logic’ is a word with a lot of different currency and different uses, so the best way to nail this down is to say what we’re really talking about here is what’s sometimes called ‘formal logic’. ![]()
0 Comments
Leave a Reply. |