Reason and Argument
Chapter 11 (2/2)
Ambiguity
• The vagueness/ambiguity distinction
should be largely familiar by now, but here
goes again:
– A word or expression is vague if it is not clear
exactly what it means.
– A word or expression is ambiguous if it is not
clear which meaning, from a number of
distinct meanings, is intended.
Ambiguity
• The phrase “Draw your weapon” might be called
by someone ambiguous because it could mean
what Clint Eastwood does in many of his
fabulous westerns or it could be what an artist
does when sketching a pistol or sword.
• We’ll be more limiting in our approach. We’ll
only call something ambiguous if the context
doesn’t clear up the situation, or if the ambiguity
results in something humorous.
Two kinds of Ambiguity
• Semantic
– When the ambiguity
stems from a particular
word or phrase having
more than one
meaning
• Syntactic
– When the ambiguity is
a result of grammar or
structure (usually
concerns which words
are intended to go
together)
Ambiguity can be very funny:
• Some good ambiguity in church bulletins:
– Bertha Belch, a missionary from Africa, will be
speaking tonight at Calvary Methodist. Come hear
Bertha Belch all the way from Africa.
– "Ladies, don't forget the rummage sale. It's a chance
to get rid of those things not worth keeping around the
house. Don't forget your husbands."
– Don't let worry kill you off - let the Church help.
– A bean supper will be held on Tuesday evening in the
church hall. Music will follow.
– Please place your donation in the envelope along with
the deceased person you want remembered.
Disambiguating:
• There are a couple of tried and true means
of making an ambiguous statement clear:
– Rewriting: substituting a different word or
phrase for the ambiguous word or phrase.
– Expanding: adding extra information that
makes the context clear.
– (see Exercise I for examples)
Equivocation
• Equivocation occurs when the same word or
phrase is used in multiple ways in the same
argument and causes an argument that appears
to be valid to really be invalid.
• Usually the different meanings of the word are
used in different ways over the course of the
whole essay or book and usually not in the same
formal argument. Often the meaning of a term
may “drift” over the course of someone’s writing.
An Example:
• Discussion question #1 on p. 364
equivocates on the term ‘public interest’,
failing to draw a distinction between things
that are in the public’s interest and things
that the public is interested in.
Exercise IV
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Semantic “drug”
Semantic “man”
Semantic “practice”
Semantic “natural”
Same as 5
Semantic “right”
No ambiguity, but non-sequitur
Syntactic, placement of “some” and “thing”
Syntactic “was/were”
Syntactic “any number”
Syntactic “fiber”
Syntactic “law”
Terms that need defining:
• Sometimes unclarity can be remedied by
taking more care in defining one’s terms.
• There are several kinds of definitions that
can be used depending on the purpose.
Lexical definitions
• These are common dictionary definitions,
that are meant to provide facts about the
standard meanings of words in a particular
language.
• They try to explain what some words
mean by using some other words that are
presumably familiar to the reader.
Disambiguating definitions
• These do not provide an account of a
given word, but specify the intended
meaning of a word that may have multiple
meanings.
Stipulative definitions
• These are used to assign a meaning to a
new term or else to assign a new or
unconventional meaning to an old term.
• Stipulative definitions are established by
explicit performatives.
• Example: from “The Virtue of Selfishness”
Precising definitions
• As disambiguating definitions are used to
resolve ambiguity, precising definitions are used
to reduce vagueness.
• Often, precising definitions take the form of
supplying standards for evaluative terms
• Precising definitions can often be argued on the
basis of their effects, which is an excuse that
some give for not supplying precising definitions
where necessary or useful.
Systematic/theoretical definitions:
• These definitions are used to establish
relationships among words and concepts
for some formal structure (usually
scientific, mathematic, or logical)
Exercise VI
1. A stipulative definition of “klurg”
2. A stipulative term for the chunks of ice
under car fenders in the winter:
3. Something that does not have a common
name but ought to: