Hi. Today I’d like to talk about parts of an argument, and how to recognize them.
Arguments have 3 parts. The first 2 of these parts are types of claims arguments contain.
These claims are usually expressed as separate sentences.
The conclusion of an argument is the claim being argued for—it is what you are trying
to prove, or show to be true, by giving your argument.
The premises of an argument are the claims being argued from—they are the evidence
or support your argument gives, in favor of the conclusion.
The 3rd part is more abstract: it is the inferential link between the premises and the conclusion.
We will also call it the argument's inference. The inferential link is harder to recognize,
because it usually is not explicitly stated in a separate sentence. Often the inferential
link is an unspoken connection between the claims being stated. (More about this later.)
To read and write arguments well, you must learn to identify what is being argued for
(the conclusion) and how it is being argued for (the premises).
Consider this example from Aristotle: “We do not choose everything because of
something else—for if we do, it will go on without limit, so that desire will prove
to be empty and futile.” In this passage, Aristotle’s first sentence
states what he is arguing for, that is, the conclusion of his argument: that there are
some things we desire for their own sake and not just for the sake of other things.
And then he supports this conclusion by saying that this conclusion being true is the only
way for us to avoid the absurd idea that our desires are unlimited.
We might use the following form to represent Aristotle’s argument:
Premise 1. If everything were desired for the sake of something else, then desire would
be unlimited. Premise 2: But desire cannot be unlimited,
for then it would be impossible for us ever to be satisfied.
Conclusion: Therefore, there must be some things we desire for their own sake.
In representing an argument this way, the horizontal line under Premise 2 is like the
line above the solution to an arithmetical problem: it distinguishes what we get out of
the argument (outputs), from what goes into it (inputs).
So how do we recognize the conclusion? The conclusion of the argument is its logical
output, its terminal point, where our minds end up when we finish following the argument’s
reasoning. It concludes the argument, in a logical sense.
Sometimes you can find the conclusion by its location in the argument.
Often the conclusion comes at the end of the argument: “...and that's why you should
vote for Candidate X for Mayor!” Sometimes the conclusion comes at the beginning of
the argument: “In this essay, I will give three reasons why Shakespeare was secretly
Catholic.” But sometimes the conclusion can be in the
middle of the argument, sandwiched between two premises: “Engineering requires a lot
of math courses, so Frank will never be an engineer. Also, he's lazy and unmotivated.”
So the location is no guarantee of finding the conclusion. We need another method to
fall back on sometimes. Writers often use indicator words to identify
their argument’s conclusion or premises. These are like signs or tags that label a
premise or conclusion. In the argument above, Aristotle uses the
word “for” to label his premise: We do not choose everything because of something
else (the conclusion) for (the reason that) if we do, it will go on without limit (that’s
the premise). Here, the word “for” is an indicator word
that labels the premise. In the engineering example I gave, the conclusion
“Frank will never be an engineer” was labeled by the indicator word “so.” Engineering
requires math (that’s a premise), so (for this reason) Frank will never be an engineer
(that’s the conclusion). Here, the word “so” is an indicator word
that labels the conclusion. Common premise indicators include: because,
for, since, as, given that, and assuming that. Common conclusion indicators: therefore,
thus, so, consequently, and hence. When writing your own arguments, you should
use indicator words to guide the reader through your reasoning.
When reading arguments, you should look for indicator words, to identify which claims
are premises and which claims are conclusions. The last way to identify the conclusion of
an argument is by figuring out where the argument as a whole is headed, the logical flow of
its claims, taken all together. This method can be helpful when there are
no indicator words. So here’s one example. “Lisa is angry
with Dalton. She hasn't spoken to him all day, and she went out of her way to avoid
him at lunch.” There are no indicator words here to tell
us which of these 3 claims is the conclusion, and which are premises.
Assuming for the moment that this is an argument, we should ask ourselves: Which of these claims
can be proved by the other two? Or, to reverse the question, Which two of
these claims are evidence for believing the third claim?
When we look at all 3 claims together, we should see that the first claim, “Lisa is
angry with Dalton,” is the conclusion. The other two claims, about Lisa's behavior
toward Dalton, give us reasons to believe that she is angry at him.
Note also that there is an unstated premise at work here too. We also need to know that
not speaking to a person and avoiding that person are signs of being angry with him.
More on that later. Here’s another example. “Too much sugar
is bad for your teeth. It causes cavities.” There are only 2 claims here. So which one
proves, or could prove, the other? We can consider both options by putting a
conclusion indicator between them: Too much sugar is bad for your teeth, therefore it
causes cavities. Hmm. Let's try putting a premise indicator
between them instead: Too much sugar is bad for your teeth, because it causes cavities.
That sounds more natural, and it better reflects the logical flow of the sentence, and the
relationship between eating sugar and cavities. “Because” is a premise indicator word,
which means that “It causes cavities” is the premise.
That means “Too much sugar is bad for your teeth” is the conclusion.
So that’s been my quick walkthrough about the parts of an argument: Premise, Conclusion
& Inference, and three different ways of recognizing conclusions: by Location, by Indicator Words,
and by Logical Flow. I hope you found this helpful. Thanks for
watching today; goodbye.