How to Understand Arguments 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: When is someone giving an argument instead of just yelling? Which parts of what they say contribute to the argument? Why are they arguing instead of fighting? What are arguments made of? What forms do they take? Think Again: How to Understand Arguments will answer these questions a more. In this course, you will learn what an argument is. The definition of argument will enable students to identify when speakers are giving arguments and when they are not. Next, we will learn how to break an argument into its essential parts, how to put them in order to reveal their connections, and how to fill in gaps in an argument. By the end of this course, students will be better able to understand and appreciate arguments that they and other people present. 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 1-5, 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.
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Think Again I: How to Understand Arguments
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How to Reconstruct an Argument
<p><b>CONTENT</b>: This week’s material will teach you how to organize the parts of an argument in order to show how they fit into a structure of reasoning. The goal is to make the argument look as good as possible so that you can learn from it. We work through the main steps of reconstruction, including putting the premises and conclusion into a standard form, clarifying the premises and breaking them into parts, arranging the argument into stages or sub-arguments, adding suppressed premises where needed to make the argument valid, and assessing the argument for soundness. The lectures begin by defining the crucial notions of validity, soundness, and standard form. You will also learn to diagram alternative argument structures, including linear, branching, and joint structures. <p><b>LEARNING OUTCOMES</b>: By the end of this week’s material, you will be able to:<ul> <li>label assuring, guarding, discounting, and evaluative terms</li> <li>determine whether an argument is valid or sound</li> <li>complete arguments by adding suppressed premises</li> <li>reconstruct arguments by and series of arguments</li> <li>classify argument structures</li></ul><p><b>OPTIONAL READING</b>: If you want more examples or more detailed discussions of these topics, we recommend <em>Understanding Arguments, Ninth Edition</em>, Chapter 5.
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Dr. Walter Sinnott-ArmstrongProfessor
Philosophy
Dr. Ram NetaProfessor
Philosophy
We're right in the middle of reconstruction.
We did stage one last week, because that's just close analysis.
In the previous lecture, we did stage two, which is to remove
excess verbiage and to put the
explicit premises and conclusion into standard form.
And this lecture is going to focus on stage three.
Which is to clarify the premises, and to
break them up where possible, without distorting them.
Let's start
with step 4, which is to clarify
the premises and the conclusion when it's needed.
So we might need to clarify them, just in order to make them easier to understand.
Or to make them less likely to mislead. And.
All that sounds pretty good. So let's try on this example.
It was hot today, so it will probably be hot tomorrow again.
Now we
need to clarify that. What exactly counts as today?
Is that you know, the time when there's daylight?
Well, does it also include night? Even though night is not day.
And what exactly do we mean by hot? How hot was it today?
And how hot will it be tomorrow?
And what, after all, is heat? And what about, it'll probably
be hot tomorrow? Probability.
That's a tough notion.
We're going to spend a whole week on that later on in the course.
There are different kinds of probability.
I want to know what kinds you're talking about here and
when you ask, for example about, will it be hot tomorrow?
What is, what is will mean?
It means it's going to happen in the future.
And what exactly is the future and is the future real, is time real?
You can go a long
way towards asking how to clarify that argument.
But that's ridiculous.
You know, we don't have to clarify a simple argument like,
it was hot today, so it will probably be hot tomorrow.
And it's lucky we don't have to clarify
every word in the argument because you couldn't.
After all when you explain one of the words or give a definition
for it, its going to be in terms of other words, and they
have to be clarified and you will never get to the end of it.
The search for perfect clarity and absolute precision is impossible.
You will never complete that search.
You will never find perfect clarity or absolute precision.
So give it up.
What we should seek is not absolute precision but adequate
precision, not absolute clarity but adequate clarity and that means that
we ought to try to clear up those parts of
the premises and conclusions that are likely to produce confusion later.
You have to be able to kind of predict, whether this part of
the argument needs to be clarified, because
people are going to get confused by it.
Now, that's not going to be easy, and there's no simple or mechanical rule to
tell you what needs to be clarified and what doesn't need to be clarified.
The only way to learn this skill.
Is to go through some examples that'll give you
models of what needs to be clarified and what done.
Sometimes the unclarity lies in a single word.
In the 1980s, Nancy Reagan used to say, "Just say 'No' to drugs".
What does that mean? Well, she is telling you not to use drugs.
To say no when somebody offers you drugs or tries to tell you to use drugs.
So in effect she's saying, you ought not to use drugs.
That's pretty clear, but now what does she mean by drugs?
Does she mean Aspirin?
I don't think she's telling me not to use Aspirin?
Does she mean prescription drugs?
I don't think she's telling me not to follow the advice of
your doctor and use the prescriptions that the doctor told you to take.
So that can't be what she means. Well maybe she means illegal drugs.
Okay. Maybe she means illegal drugs.
What about heroin or cocaine? Yes, that's what
she's telling you not to do.
She's definitely telling you not to take illegal drugs.
But then there's somethings in the middle.
She might be telling you not to
take dangerous drugs, whether they're illegal or not.
What about.
Nicotine. What about alcohol?
Those are both dangerous drugs.
At least when you used to excess, alcohol is very dangerous
and smoking can lead to lung cancer and that's how most people
get nicotine.
So maybe she's telling you not to take nicotine or
alcohol in addition to illegal drugs like heroine and cocaine.
Now it's not clear. So how do we clear it up?
Well, you want Nancy Reagan's claim to look as good as possible.
Remember, you're always trying to make the argument look as good as possible.
And one way to make it look good is
to make your claim no more than she has to claim.
So, she could be claiming that in addition to heroin and cocaine,
you shouldn't take alcohol and nicotine, but probably or at at least more
[INAUDIBLE]
she's telling you not to take illegal drugs.
She had to choose between interpret her as saying don't
take any illegal drugs and don't take any dangerous drugs.
And it seems like the more charitable interpretation that makes
her claim look more plausible is don't take any illegal drugs.
So we could clarify her claim, just say "No" to drug,
by interpreting it to mean you ought not to take any
illegal drugs. So in general then, the lesson is.
That, when there are options about how to clarify a certain sentence, we ought to
pick the most charitable option that makes the claim look as good as possible.
Here's another example, where the unclarity can
be traced to a single word, but
in this case it's the word that, and it's not clear what it refers to.
So imagine that someone argues
like this.
They say, she claims that our strategy
won't work because the enemy knows our plan.
But that is a big mistake.
What is that refer to?
That could refer to, that is the word that could refer to,
that the enemy knows our plan.
Someone says, that's a mistake, they might be saying it's a mistake to think that the
enemy knows our plan, but it could refer to the claim that our strategy won't work.
They could be saying it's a mistake to think
our strategy won't work or they could be saying,
but the mistake is to think that the enemy
knowing our plan, is enough to make it not work.
They might be saying, it's not that it
won't work because the enemy knows the plan.
Or, here's a fourth possibility.
They could be saying, that is a mistake to think that she claims that.
That's not what she claims.
So, there're four different ways to interpret this argument.
And in order to figure out how to interpret
it we have to figure out, which of those
is most likely as an interpretation of what the arguer is trying to say.
And that's going to depend on which one makes the argument look the best.
Now in this example, it's not clear which interpretation is the
best because someone might give that argument in a context where they're
saying the mistake is to think she claims that, but in
other cases they might be saying that the mistake is to think
that the enemy knows our plan. They don't really know our plan.
And in other cases, they might be claiming that other things, you're mistaken.
So, we need to figure out what the person is saying, but that
could depend on the particular context and might vary from context to context.
Now, these unclarities seem unintentional. But sometimes people use unclarity.
To hide problems with their argument. To try to fool you.
So imagine a politician says, we need to stop our enemies and stand by our friends.
So we must remain strong and resolute.
Well, if somebody starts arguing like that you ought to be asking yourself.
Who do they think our friends are?
Who do they think our enemies are? What do they mean, stop our enemies?
Are they calling for military action?
How do they think we ought to stop our enemies?
And standing by our friends, does that mean we
ought to support them no matter what they do?
There're lots of questions that you would want to ask to clarify
exactly which claim is being made before you accept something like this.
Heres another claim that might be made by an opponent of a first politician.
"We have to help the needy," wait a minute.
Which people are needy? I mean everybody needs something.
How needy do you have to be to be needy? And, we ought to help the needy?
Well, how are we going to help them?
Does that mean we just give them whatever they want?
Or, what are we supposed to give them, and when are we supposed to
give them, and how much are we willing to spend on giving it to them?
Politicians on both sides of the political spectrum
make vague claims that need to be clarified.
Before you should be willing to endorse one or the other of those claims.
If you try to decide, what to believe
before you know exactly what the claim means,
before you've clarified it, you could end up committing yourself to
all kinds of nonsense and all kinds of very problematic positions.
You could get yourself into a lot of trouble.
That's why we need to clarify the terms in arguments.
Now, one special way in which premises need to be clarified, is that
they need to be broken up into smaller parts, where you can do that.
And the point of this is that
the smaller parts are going to be easier to understand,
and easier to access whether they are true or not.
So step 4, clarify the premises, belongs together
with step 5, break up the premises into parts.
What needs to be broken up?
Well, the explicit premises and sometimes the conclusion, as well.
Here's a simple example.
That shirt looks great on you and it's on sale.
So you ought to buy it.
We might put that in standard form like this.
That shirt looks great on you and, it's on sale, is the premise.
And the conclusion is, you ought to buy it.
But notice, that the premise has two parts, joined by an and.
So, we could break
them up.
And have the first premise, that shirt looks great
on you, and the second premise, it's on sale.
And then the conclusion is, you ought to buy it.
Breaking it up like that is supposed to make
it easier to asses the premise for truth or falsehood.
Now in this case it doesn't make it much easier, because it was so simple to begin
with, but we'll see that breaking up premises will
really help when we get to more complex examples.
So, it makes sense to break up premises. Well, at least sometimes.
We should not break up premises when breaking them up distorts the argument.
Here's an example of that.
We still need to add either one more cup of white sugar or one more cup of brown
sugar to complete the recipe, so we've gotta add another cup of ingredients.
Then one way to represent that argument would be to say
that premises, we still need to add either one more cup
of white sugar or one more cup of brown sugar and
the conclusion is, we have another cup of ingredients to add.
But we could break it up because it's got parts.
We could change the argument into, we still
need to add one more cup of white sugar.
That's the first premise.
And the second premise is, we still need to add one more cup
of brown sugar and then the conclusion is, we have one more
cup of ingredients to add, but that argument doesn't make any sense.
If we've got to add one of white and one of
brown, we don't just have one more cup of ingredients to add.
And as always, we're supposed to be making the argument look good.
And that change made it look bad. And the problem is that here,
we broke up the word or.
Because it's one cup of white or one cup of brown.
And presumably you didn't know which it was
or maybe you had a choice between the two.
But you weren't suppose to both.
That would be too much. And the word or signals that.
So, in general, you should not break up, when the word that joins the
two is or, but it's okay to break up when the word that joins
the two is and.
You still gotta be careful about context, it's not
always going to work that way, but as a general rule.
You know, that usually works. Other cases are even trickier.
One particularly problematic case is dependent clauses.
Here's an example.
Nancy finished all her homework because all she had to
do was write 25 lines of poetry, and she wrote
two sonnets which have 14 lines each.
The dependent clause is, which have 14 lines each.
And the question is, how do we fit that into standard form?
Well, here's one stab.
The first premise can say, all she had to do is write 25 lines of poetry.
And the second premise can be, she wrote two sonnets which have 14 lines each.
And then the conclusion
is, Nancy finished all her homework. Now the question is, can we
break up that second premise into two different parts, and it seems like we can.
We should be able to represent the argument so the first
premise is, all she had to do was write 25 lines of
poetry and the second premise says she wrote two sonnets, and the
third premise says sonnets have 14 lines each, and the conclusion is,
she finished all her homework.
In this case, breaking down the premise
actually helps us understand and assess it.
Because we can decide whether it's really true,
for example, that sonnets have 14 lines each.
That's going to be a question.
If the answer is no, then the argument might fail.
If the answer is yes, at least for
standard sonnets, so the argument looks pretty good.
Contrast that example with this one.
Our legal system isn't fair, because
authorities go easy on white collar criminals
who have been allowed to get away with their crimes in recent years.
Well the premise could be authorities go easy
on criminals who have been allowed to get
away with their crimes in recent years, and
the conclusion is our legal system isn't fair.
Now the question is can we break
up that first premise.
because it has that deep ended clause who have been
allowed to get away with their crimes in recent years.
Well, that depends.
Because the person giving the argument might be saying
that authorities go easy on all white collar criminals.
And they might be saying, that authorities only
go easy on a certain subset of white-collar criminals.
Namely, the subset that have
been allowed to get away with their crimes in recent years.
If the premise is about all white-collar criminals, then we can break it up.
So that one premise says, authorities go easy on white-collar criminals.
And the next premise says, white-collar criminals have been
allowed to get away with their crimes in recent years.
But if the arguer is only talking about some white-collar criminals.
And admits that other white-collar criminals have not
been allowed to get away with their crime.
He's only saying that.
Authorities go easy on those white-collar criminals who
have been allowed to get away with their crime.
That subset of white-collar criminals and then
it would distort the argument to break
it up, because if you do break it up, then that second premise says white-collar
criminals have been allowed to get away with their crimes in recent years.
And if some of 'em haven't, then that premise turns out to be false.
So if you break it up, you can criticize it by
pointing out that it doesn't really apply to all white-collar criminals.
But if you leave it as a single premise, then it's not subject to that criticism.
So, if you want to be charitable.
You probably ought to keep this
premise together, unless you know on independent grounds, that the person was
making that claim about all white-collar criminals, and not just a subset.
So, to make that argument look better, we don't break up the premise.
And the general lesson is that with
dependent clauses like that, and which, and who.
You have to look very carefully to figure
out what the speaker wanted to say and what's
going to make their argument look best and use that information
to determine whether or not to break up the premise.
There are no airtight rules as always, so
we needed a few exercises to practice this skill.
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