What is an Argument?

http://www.criticalthinkeracademy.com

This video introduces the concept of an ARGUMENT as the term is used in logic and argumentation.

SPEAKER 1: 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 the 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 a conclusion.

The remaining claims
are called 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 could 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 your
logical properties,

or considering whether the
premises are true or not,

putting an argument
in standard form

can make life a lot easier.

And 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?

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
Jon is a musician,

but the conclusion only follows.

If you assume that all
musicians, or most musicians,

can read music,
which is not 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 is 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.

Being able to do
this is actually

an important skill in logic.