We’ve seen that one purpose in giving a definition of a word is to tell how the word is normally used. Another purpose is to make a joke. Very often, a definition is designed to make the word be more precise. A definition of dog as "an animal like that pet over there" would be of little help to a biologist. A biologist needs a more precise definition. Every time a high court judge makes a decision in a case of assault, it sets a precedent that makes the legal term assault more precise.
Suppose I hire you to visit the corner of Watt Avenue and Marconi Boulevard and to count the number of nice cars that pass by during lunchtime each day for a week.
You, the logical reasoner, will think to ask me to define my key terms "nice car" and "lunchtime" if I hadn’t done this already. Suppose I define "nice car" as a car that currently retails for over $30,000; and define "lunchtime" to mean from noon to 1:30 P.M. OK, now things are clearer.
At the time cars were invented, horses were a better-known source of power, so it was common to say the more powerful of two cars had more "horsepower." The term was also used to represent the power of water wheels, motors, and even people. Clarity was added to all this when the experts finally agreed on a more precise definition:
Definition: One horsepower is the power needed to raise a weight of 550 pounds by one foot in one second.
Precising definitions are definitions that make the correct meaning more precise. We have just seen three examples of precising definitions: for "nice car," "lunchtime," and "horsepower."
As you may have noticed from the above discussion, you can't always find a proper definition in the dictionary. There is no definition of "nice car" there.
When a new law is written, it often begins with a precising definition of a key term, but then when court cases reveal that even with this definition there isn't sufficient precedent or established usage to determine how the term applies in some important case, then jurors, legislators and judges step in to make the definition even more precise.
Let's look at an example. The Fourth Amendment to the U.S. Constitution prohibits "unreasonable searches and seizures." What exactly does that term mean? Well, it's a matter of a mix of common sense, legislation and judicial decision. In the 1991 case of California v. Hodar D, the Court considered the case of a suspect who threw away a packet of drugs while running from the police. The drugs were then confiscated by the police. Have those drugs been seized unreasonably? "Yes," said the defense lawyer. "No," said the prosecutor. To resolve the dispute, the Court had to more precisely define "unreasonable seizure." It decided that if the suspect keeps running after dropping his materials, then no unreasonable seizure of those materials has occured and the materials will later be admissible as evidence.
In redefining terms used in a court decision, the judge is guided in part by what can be learned about the intentions of the legislators who enacted the law, and in part by what the judge conceives to be in the public interest. Other people who provide precising definitions usually are not guided by those aspects of the situation. Consider anthropologists. At the time that the famous anthropologist Dr. Louis Leakey sent the 26-year-old Jane Goodall into Tanzania in Africa to study chimpanzees, the term "human being" was defined in part as "the tool-making animal." We humans were known as "Man the Tool Maker."
But Dr. Goodall made a remarkable discovery. She found a chimp that can strip leaves off a straight twig, insert the twig into the entrance of a termite mound, wait a few seconds, pull out the twig loaded with termites, and use its lips to strip off the termite snacks. Termite shish-kabob. This was the first scientific discovery that another species makes tools. The behavior is not instinctual and must be passed on from one generation to the next by teaching.
When Goodall submitted her report about using twig-tools to get termites, Dr. Leakey wrote back, “Now we will have to redefine tool or redefine human or accept chimpanzees as humans. After some turmoil within the community of professional anthropologists, they decided to redefine "human." Dictionary writers had to follow their lead.
Definitions serve other purposes besides making a term more precise. Powerful political institutions can exert their power by defining terms their own way. An ordinance was once proposed to the city of Cambridge, Massachusetts, to outlaw "all animal experimentation involving pain with inadequate anesthesia." It required adequate anesthesia for all experimentation on animals. However, it permitted inadequate anesthesia for rats and mice. Lest you think there is an inconsistency here, the ordinance noted that rats and mice are not animals, at least not according to the U.S. Department of Agriculture's definition of animals, to which the ordinance referred. Evidently, the Department of Agriculture has the power to define animals not to be animals. Such is the power of government, the power of the word, the power to control definitions.
Not only do people create definitions for a variety of purposes other than simply to describe how everybody has been using the word, but they also use a variety of definitional techniques. Let's consider some especially important ones. If you did not know what a Labrador Retriever is,
I might be able to define the term by pointing to a specific dog and saying, "This is what I mean." A definition by pointing is an ostensive definition. Ostensive definitions are a kind of definition by example. If I define physical science as "something like geology, chemistry, astronomy, or physics," I am giving a definition by example. Dictionaries cannot use ostensive definitions, but occasionally they do use definitions by example. A dictionary definition is called a lexical definition because dictionaries are called lexicons. Here is an example of a lexical definition that is not a definition by example:
Vixen means "female fox."
The definition is correct, so the definition's sentence is a true sentence.
A stipulative definition stipulates how a new term is to be used from now on. If I define the term boke to be a broken coke bottle, I have coined a new term for our language, although there isn't much chance my definition will be adopted by other speakers. In 1840, in his introduction to The Philosophy of the Inductive Sciences, William Whewell wrote: "We very much need a name to describe a cultivator of science in general. I propose to call him a 'scientist.'" Whewell's stipulative definition caught on. It has now become a correct lexical definition.
Persuasive definitions are another category of definitions. Take the definition of atheist proposed by William, an acquaintance of mine: "By atheist I mean a non-Christian pervert who will rot in hell." Well, the definition is not especially accurate because it doesn't reveal the way most other people use the term atheist. It’s more of biased description or persuasive definition, not a lexical one.
Sometimes a definition of a term will offer some operation or procedure to tell whether something should be called by that term. The procedure of asking a woman whether she is pregnant and taking a "yes" answer to indicate pregnancy would be an operational definition of pregnant that a social science researcher might use when studying whether pregnant women have a better diet than other women. This operational definition isn't what most of us would give if we were asked to explain what pregnant means, but it could succeed at identifying who is and who isn't pregnant and so deserves to be called a definition of “pregnant.”
Create an operational definition of popular TV show.