Example
2 - Summary
Here’s
what we learned in this example:
Reason Indicator Expressions
Reason indicator expressions tell us that an idea is being given as a reason to believe another idea.
This means that reason indicator expressions introduce reasons (like conclusion indicator expressions introduce
conclusions).
There are many reason indicator expressions, including “Y because X” or “Because X,
Y.” “Y, since X” or “Since X, Y.” “Given that X, Y” or “Y, given that X.” “Assuming that X, Y” or “Y, assuming that X.” “Inasmuch as X, Y” or “Y, inasmuch as X.” “In
view of the fact that X, Y” or “Y, in view of the fact that X.” “Y. The
reason is that X” “Y. After all, X.” In all of these sentences, X is the reason to
believe Y. All these sentences would be diagrammed
like this:
X
A
Y
Diagramming Example 2
Our argument is
diagrammed as follows:
2)
“History is not the most important
subject because some other subject is at least as important as history.”
1. History is not the most important subject.
2. Some other subject is at
least as important as history.
2
A
1
Notice that
·
The reason
indicator expression “because” introduces the premise in the passage, because
the premise is the reason to believe the conclusion.
Evaluating Example 2 – Premises that Assume the
Conclusion
When evaluating an
argument, we need to ask ourselves:
1) “Do we think that this
premise is true?” and
If the
answer to either one of these questions is “no,” the premise is bad.
In this case the premise can’t
be believed by people who don’t already believe the ultimate
conclusion. We say that such premises assume the conclusion.
In this case, that makes the
entire argument bad because there’s no other reason to believe the ultimate conclusion.
2) “History is not the most
important subject because some other subject is as at least as important as
history.”
1. History is not the most important subject.
2. Some other subject is at
least as important as history.
2 L
A L
1
Let’s take a look
at another example.