9 9su p p r e s s e d P r e m i s e sbe true for the conclusion to follow from the premises. This process of making
everything explicit enables us to assess these background assumptions directly.There is one obscure exception to the premise that only a natural-born citizen
may become president of the United States. The Constitution does allow a
person who is not a natural-born citizen to become president if he or she was
“a citizen of the United States at the time of the adoption of this Constitution.”
This exception is said to have been added to allow Alexander Hamilton to run
for president, but it obviously does not apply to Schwarzenegger or to anyone
else alive today. Nonetheless, this exception keeps the argument from being
sound in its present form. Reformulate the final stage of the argument to make
it sound.exercise viiiLinguistic Principles
Often an argument is valid, but it is still not clear why it is valid. It is not
clear how the conclusion follows from the premises. Arguments are like
pathways between premises and conclusions, and some of these pathways
are more complicated than others. Yet even the simplest arguments reveal
hidden complexities when examined closely. For example, there is no ques-
tion that the following argument is valid:
(1) Harriet is in New York with her son.
∴(2) Harriet’s son is in New York.
It is not possible for the premise to be true and the conclusion false. If asked
why this conclusion follows from the premise, it would be natural to reply
that:
You cannot be someplace with somebody unless that person is there, too.
This is not something we usually spell out, but it is the principle that takes
us from the premise to the conclusion.
One thing to notice about this principle is that it is quite general—that is,
it does not depend on any special features of the people or places involved. It
is also true that if Benjamin is in St. Louis with his daughter, then Benjamin’s
daughter is in St. Louis. Although the references have changed, the general
pattern that lies behind this inference will seem obvious to anyone who un-
derstands the words used to formulate it. For this reason, principles of this
kind are basically linguistic in character.
If we look at arguments as they occur in everyday life, we will discover
that almost all of them turn on unstated linguistic principles. To cite just one
more example: Alice is taller than her husband, so there is at least one woman
who is taller than at least one man. This inference relies on the principles that97364_ch05_ptg01_079-110.indd 99 15/11/13 9:53 AM
some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materiallyCopyright 201^3 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights,
affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.