14.3.4: Reasoning by Analogy/Comparison

Reasoning by Analogy/Comparison

Comparison reasoning is also known as reasoning by analogy. This type of reasoning involves drawing comparisons between two similar things, and concluding that, because of the similarities involved, what is correct about one is also correct of the other. There was once an ad for alligator meat that presented this comparison; "When you try alligator meat just remember what is considered exotic food today may often become normal fare in the future. This was the case with lobster. About 75 years ago, lobster was thought of as poor man's food; many New Englanders would not even think of eating it. Today, of course, lobster is a delicacy savored by many people." This type of reasoning wants us to conclude that alligator meat is to humans today, as lobster meat was to humans 75 years ago. And since lobster is now a delicacy so will be alligator meat.

There are two types of comparisons: figurative and literal.

Literal comparisons attempt to establish a link between similar classifications; cars to cars, states to states, people to people. For instance, you can compare a Ford compact car with a Toyota compact car; the lottery in one state with the lottery in another state; how your parents treat you with how your best friend is treated by her parents. In these comparisons, similar classifications are being used for the purposes of making the analogy. Literal comparisons can provide logical proof for the point being made and thus can increase the validity of the argument. A literal comparison would be considered an "apples to apples" argument.

Figurative comparisons attempt to link similarities between two cases from different classifications. Jim Baker of the Bush 2000 campaign, argued after the 5-4 Supreme Court decision awarding the state of Florida to Bush, “Saying George W. Bush stole the Presidency from Al Gore is like saying someone tried to steer the Titanic after it had already hit the iceberg.” Figurative comparisons carry no weight in terms of providing logical proof for an argument. They can, however, be very effective for the purpose of illustration and persuading an audience. When someone says, "You're comparing apples to oranges," they are really saying that you're making a figurative comparison; that is, you are comparing unlike things.

The line between a literal and figurative analogy is not always clear. Instead of a comparison being totally figurative or totally literal, the comparison can vary by degree. There are few literal comparisons that can be made between a person and a computer, for example. A person to an animal may have some overlapping similarities. The more figurative the comparison or analogy, the less logically valid the argument. The more literal the comparison is, the more logically valid the argument.

Tests of reason by comparison/analogy:

• To be considered as proof, the analogy must be a literal one. The further advocates move away from figurative comparisons and toward the literal comparison end of the continuum, the more validity they secure for their argument. Figurative comparisons carry no logical argumentative influence at all.
• The cases need to contain significant points of similarity. The greater the number of important or major similar points between the cases, the easier it is to establish the comparison as a sound one. However, no matter how many points of similarity can be established between the two cases, major points of differences can destroy the analogy. Children often try to convince a parent to let them do or try something the parent is opposed to by comparing themselves to another child. They point out they are the same age as the other child, they are in the same grade in school, the child lives in the same neighborhood as they do, thus they should be allowed to do what the other child is allowed to do. This seems to be a very effective argument by comparison until the parent says, you are not that child or we are not their parents. To the parents, these points of difference destroy the comparison the child is trying to make.
• Cumulative comparison reasoning will produce a more probable conclusion. The greater the number of cases a person can use for the purpose of comparison, the more valid the comparison. If a student has been to more than one college or has had
  many instructors, he or she can evaluate the quality of the teachers by comparing them. The validity of his or her conclusion is increased as the number of teachers compared increases.

Bad Analogy in Real Life

May 23, 2016
(CNN) Veterans Affairs Secretary Bob McDonald downplayed the time it takes for veterans to receive medical treatment by comparing the "experience" of waiting for health care to Disneyland guests waiting for a ride. "When you go to Disney, do they measure the number of hours you wait in line? Or what's important?" McDonald told reporters at a Christian Science Monitor breakfast in Washington. "What's important is what's your satisfaction with the experience?" American Legion National Commander Dale Barnett excoriated McDonald: "The American Legion agrees that the VA secretary's analogy between Disneyland and VA wait times was an unfortunate comparison because people don't die while waiting to go on Space Mountain."