As
we’ve seen, philosophy is the activity
of considering questions that can’t be answered empirically and addressing them
by thinking rationally.
Let’s
figure out what “thinking rationally” means by looking at possible answers to
the question “What should Ann major in?”
Here’s
the first answer.
1)
“History is the most important subject therefore Ann should major in history.”
This
passage answers the question “What should Ann major in?” and backs up its
answer with a reason to think that its answer is true. This makes the passage
an argument.
§
An argument
is a unit of reasoning that attempts to prove to its audience that a certain
idea is true by citing other ideas as evidence.
§
The idea that the argument tries to prove true is called the
“ultimate conclusion.”
All arguments have exactly one ultimate conclusion.
§
Ideas which the argument uses as evidence for the ultimate
conclusion, but which the argument just assumes to be true without giving us
any reason to believe them, are called “premises.”
All arguments have at least one premise, and they can
have any number of them.
§
Intermediate ideas on the way from the premises to the
ultimate conclusion are called “subconclusions.”
An argument does give us reason to believe a subconclusion but it’s not
what the argument is ultimately trying to get us to believe. Instead,
the subconclusion is used as a reason to believe still another idea.
Arguments don’t need to have any subconclusions at all, although most of them do have some.
§
An inference is the connection that holds between a set of
ideas, call it ‘R’ for “reason,” and another idea, call it ‘C’ for
“conclusion,” when the truth of the ideas in R is supposed to establish the
truth of C.
You’ll
understand all that much better once we actually start recognizing the
parts of an argument, identifying the ultimate conclusion, the premises, and
the subconclusions (if any). But how can we do this?
Remember,
the ultimate conclusion is what the passage is trying to prove. Premises are taken
for granted by the argument without support. And subconclusions are
intermediate steps. The argument does give us reason to believe the
subconclusions and then goes on to use the subconclusions to prove other ideas.
So, in order to identify the parts of
an argument, it helps to do two things:
1. Start out by asking, “What is the main idea
that this argument is trying to prove?” The answer to that question is the ultimate
conclusion of the argument.
2. Then, for all other important ideas in the argument,
ask “Does the argument give us reason to believe that this is true, or does the
argument just take this for granted?”
If the argument does give us reason to believe an
idea, it’s a subconclusion.
If the argument doesn’t give us reason to believe an
idea, but instead just takes the idea for granted, it’s a premise.
Let’s
try it out. For each of the underlined sentences in the argument we just saw,
determine whether it’s the ultimate conclusion, a premise, or a subconclusion
in the argument. Rest the mouse over your answer to see if you’re right.
1) “History
is the most important subject therefore Ann should major in history.”
“History is the most important
subject” is
the ultimate conclusion of this argument.
“Ann
should major in history” is
the ultimate conclusion of
this argument.
Now let’s see how we draw a picture of this argument that will
help us to understand and evaluate it. In other words, let’s see how we can diagram this argument.