The fallacy of equivocation occurs when a term or word switches meaning in the course of the argument, that is, when a term or word expresses one meaning in one premise and another meaning in another premise or conclusion.
Let us consider the example below.
Example 1
Philosophy is an art.
But art is practiced by painters.
Therefore, philosophy is also practiced by painters.
As we can see, the premises of the argument above are plausible, and the argument appears to be valid. However, the term “art” is used in two different senses. In the first premise, the term art refers to a skill that requires creativity, imagination and the ability to think critically, while in the second premise it refers to the “fine arts” or the cultural institution which involves the fine arts (that is, painters in the case of the example above.
It must be noted that although it may be true that painters practiced the fine arts, it is not necessarily true that they practiced all the skills that involved creativity, imagination and the ability to think critically.
Let us consider another example.
Example 2
Logic is the study of arguments. Well, that is one course that I could ace. I know all about arguments. I have learned from experts. You should hear the arguments my parents have.
As we can see in the argument above, the arguer may conclude, in effect, that he would do well in the study of arguments because he knows all about arguments. But it is important to note that the word “argument” here is being used in two different senses. In the first sense, it means “reasoning”, but in the second sense it means “quarreling”. If we substitute the two senses of the word “argument” here, then we are able to clarify what the arguer, in fact, had said: that he would do well in the study of “reasoning” because he knows all about quarreling. This, of course, does not follow.
The examples below will further illustrate the fallacy of equivocation.
Example 3
“Impartiality” means not taking sides in a dispute; I had hoped that the judge would be impartial, but he ruled against me.
Example 4
All stars are heavenly bodies. But Angelina Jolie and Brad Pitt are stars. Therefore, there is a good reason to believe that Angelina Jolie and Brad Pitt are heavenly bodies.