Analogies involve a comparison of ideas, items, or circumstances. When you compare two things that actually exist, you are using a literal analogy—for example, “Germany and Sweden are both European countries that have had nationalized health care for decades.” Another type of literal comparison is a historical analogy. In Mary Fisher’s now famous 1992 speech to the Republican National Convention, she compared the silence of many US political leaders regarding the HIV/AIDS crisis to that of many European leaders in the years before the Holocaust.
My father has devoted much of his lifetime to guarding against another holocaust. He is part of the generation who heard Pastor Niemöller come out of the Nazi death camps to say, “They came after the Jews and I was not a Jew, so I did not protest. They came after the Trade Unionists, and I was not a Trade Unionist, so I did not protest. They came after the Roman Catholics, and I was not a Roman Catholic, so I did not protest. Then they came after me, and there was no one left to protest.” The lesson history teaches is this: If you believe you are safe, you are at risk.
A figurative analogy compares things that are not normally related, often relying on metaphor, simile, or other figurative language devices. In the following example, wind and revolution are compared: “Just as the wind brings changes in the weather, so does revolution bring change to countries.”
When you compare differences, you are highlighting contrast—for example, “Although the United States is often thought of as the most medically advanced country in the world, other Western countries with nationalized health care have lower infant mortality rates and higher life expectancies.” To use analogies effectively and ethically, you must choose ideas, items, or circumstances to compare that are similar enough to warrant the analogy. The more similar the two things you’re comparing, the stronger your support. If an entire speech on nationalized health care was based on comparing the United States and Sweden, then the analogy isn’t too strong, since Sweden has approximately the same population as the state of North Carolina. Using the analogy without noting this large difference would be misrepresenting your supporting material. You could disclose the discrepancy and use other forms of supporting evidence to show that despite the population difference the two countries are similar in other areas to strengthen your speech.