Circularity and Begging the Question

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來自 Duke University 的課程

Think Again IV: How to Avoid Fallacies

118 個評分

Duke University

Think Again IV: How to Avoid Fallacies

118 個評分

How to Avoid Fallacies Think Again: How to Reason and Argue Reasoning is important. This series of four short courses will teach you how to do it well. You will learn simple but vital rules to follow in thinking about any topic at all and common and tempting mistakes to avoid in reasoning. We will discuss how to identify, analyze, and evaluate arguments by other people (including politicians, used car salesmen, and teachers) and how to construct arguments of your own in order to help you decide what to believe or what to do. These skills will be useful in dealing with whatever matters most to you. Courses at a Glance: All four courses in this series are offered through sessions which run every four weeks. We suggest sticking to the weekly schedule to the best of your ability. If for whatever reason you fall behind, feel free to re-enroll in the next session.We also suggest that you start each course close to the beginning of a month in order to increase the number of peers in the discussion forums who are working on the same material as you are. While each course can be taken independently, we suggest you take the four courses in order. Course 1 - Think Again I: How to Understand Arguments Course 2 - Think Again II: How to Reason Deductively Course 3 - Think Again III: How to Reason Inductively Course 4 - Think Again IV: How to Avoid Fallacies About This Course in the Series: We encounter fallacies almost everywhere we look. Politicians, salespeople, and children commonly use fallacies in order to get us to think what they want us to think. Think Again: Fallacies will show how to identify and avoid many of the fallacies that people use to get us to think the way they want us to think. In this course, you will learn about fallacies. Fallacies are arguments that suffer from one or more common but avoidable defects: equivocation, circularity, vagueness, etc. It’s important to learn about fallacies so that you can recognize them when you see them, and not be fooled by them. It’s also important to learn about fallacies so that you avoid making fallacious arguments yourself. Suggested Readings Students who want more detailed explanations or additional exercises or who want to explore these topics in more depth should consult Understanding Arguments: An Introduction to Informal Logic, Ninth Edition, Concise, Chapters 13-17, by Walter Sinnott-Armstrong and Robert Fogelin. Course Format Each week will be divided into multiple video segments that can be viewed separately or in groups. There will be short ungraded quizzes after each segment (to check comprehension) and a longer graded quiz at the end of the course.

從本節課中

Fallacies of Vacuity and Circularity

CONTENT: Now we will describe another common set of fallacies: fallacies that occur when an argument makes no progress from its premises to its conclusion. Sometimes, arguments make no progress because the conclusion is already contained in the premises. Sometimes, arguments make no progress because the conclusion is presupposed by the premises. And sometimes, arguments make no progress because the premises don’t make any claim at all, even if they might sound like they do. When you know how to identify such fallacies, you will find that they are more common than you think! LEARNING OUTCOMES: By the end of this section you will be able to: identify various kinds of circularity or vacuity where they occur OPTIONAL READING: If you want more examples or more detailed discussions of these topics, we recommend Understanding Arguments,Ninth Edition, Chapter 16.

Fallacies of Vacuity4:13

Circularity and Begging the Question4:50

Self-Sealers8:11

與講師見面

Dr. Walter Sinnott-Armstrong
Professor
Philosophy
Dr. Ram Neta
Professor
Philosophy

Now that we've introduced the topic of fallacies of acuity,

today we're going to talk about circularity and begging the question.

So what are these things?

What is circularity and what is begging the question?

Circularity is a fallacy that results when an argument's premises contain

its conclusion, when the conclusion is right there among the premises.

Now, this is a really egregious fallacy, not one that people

are likely to make very often, because it's so easy to notice.

But let me give you an example, just so you can see what I'm talking about.

So consider this simple example of circularity.

Premise one, this argument, this very argument, has a premise.

Premise two, this very argument has a conclusion.

Therefore, conclusion, this argument has a conclusion.

Now notice, the conclusion of that argument

is the same proposition as premise two of that argument.

In other words, the conclusion is right in the premises.

That's a circular argument.

That's an example of a fallacy of circularity.

That's pretty hard to miss, and

that's not the kind of fallacy that most people often make.

But circularity is one very egregious example of a more general

kind of fallacy that lots of people make, and that's called begging the question.

So what's begging the question?

Well, begging the question is a kind of fallacy that results when you can't

have any reason for accepting the premises of the argument unless you

already have some independent reason for believing the conclusion.

Right, so in a certain sense the argument assumes what it sets out to prove, because

unless you already have a good reason for believing the conclusion to be true,

you can't have a good reason for believing the premises to be true.

And without having a good reason for believing the premises to be true,

the argument can't give you any insight.

It can't teach you anything.

No argument can teach you something unless you have a good reason for

believing the premises of that argument to be true.

So that's the fallacy of begging the question.

Now, what's an example of that?

These examples can be a little more subtle.

Right, because not all forms of begging the question are circularity.

Let me give an example of begging the question that doesn't involve circularity.

So consider this argument.

Again, it's a simple argument.

The Pope says that he is infallible.

Premise two, whatever the Pope says is always right.

Therefore, conclusion, the Pope is infallible.

Now notice that argument is obviously valid, right.

If the Pope says that he's infallible and whatever he says is right,

then he must be right to say that he's infallible.

In fact, that's how the doctrine of papal infallibility was first established was by

papal decree.

I'll let you look that up.

Anyhow, if the premises of the argument are true, the conclusion has to be true.

So the argument is valid, but even though the argument is valid, in fact,

even if the argument is sound, the argument is still a fallacy.

And the reason it's a fallacy is that we can't have any good reason for

believing premise two of the argument, unless we already have some reason,

independently of the argument, for believing the conclusion.

Right, unless we already know that the pope is infallible,

why should we believe that whatever the pope says is always right?

Well, maybe there is some other reason, but unless that additional reason

is supplied In the argument, this argument begs the question.

It begs the question, because it relies on premises

that we have no reason to believe unless we already have a good reason to believe

the conclusion independently of the argument itself.

So this argument is an example of begging the question, but

notice it's not an example of circularity.

The conclusion of the argument that the Pope is infallible,

that conclusion is not in the premises.

It's not one of the premises.

Right, there are two premises in the argument, and

neither of those premises says precisely that the Pope is infallible.

So this argument is an example of begging the question, but

it's an example of begging the question that doesn't involve circularity.

And that sort of fallacy is much harder to notice, much easier to make, and

much more common in everyday life.

You can see some examples right now.

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