1. Reasoning by comparison
Analogy
Reasoning by comparison

2. Argument by Analogy
Analogies are based on similarity, comparison, or precedent.
The inference being made is that two things which resemble each other in certain known respects will resemble each other in unknown respects.
example: Many who oppose abortion compare it to the Holocaust, when millions of Jews were exterminated by the Nazis.
example: An atheist says, “I don’t believe in Jesus any more than I believe in the Easter Bunny, Santa Clause, or the Tooth Fairy.”

3. Some sample analogies
Plato compared the world we perceive to shadows on a cave wall.
Comparing human consciousness to a flame on a candle
Comparing scientists involved in cloning research to Dr. Frankenstein.

4. Recent arguments using analogy
Comparing Barack Obama to John F. Kennedy
Hillary Clinton compared herself to “Rocky”
Comparing marijuana laws with the prohibition era
Comparing the war in Iraq with the war in Viet Nam
Comparing Osamu Bin Laden, Saddam Hussein, and Kim Jong il.

5. Political cartoons often rely on visual analogies

6. The holocaust and factory farming?
“[A]s long as human beings will go on shedding the blood of animals, there will never be any peace. There is only one little step from killing animals to creating gas chambers à la Hitler and concentration camps à la Stalin. … There will be no justice as long as man will stand with a knife or with a gun and destroy those who are weaker than he is.”      —Isaac Bashevis Singer

7. Analogies about life
“Life is like a box of chocolates…” (Forrest Gump)
“Life is a sport. Drink it up” (Gatorade)
“It’s a jungle out there.”
Life is a “rat race.”
“Being a student is like being a sponge. The less you know the more you can soak up.”
“Employees are like nails. You have to hit them on the head to get them to work.”

8. Politics as Sports analogies
“She hit that one out of the park.”
“They’re not pulling any punches.”
“That was like hitting a jumper at the buzzer.”
“He gave a great half-time speech.”
“He’s got the ball, now he’s got to run with it”

9. applications of analogies
in politics: comparing the Clinton-Lewinsky scandal to Watergate
In economics: viewing economic competition as the “survival of the fittest.”
Comparing the target of a scandal to Humpty Dumpty

10. More applications of analogies
In history: likening France’ refusal to vote for an invasion of Iraq as analogous to Neville Chamberlain’s appeasement of Hitler leading up to World War II.
in science and medicine: likening the human brain to a computer, HIV to an invading army, the human heart to an electric pump, DNA molecule is like a ladder

11. Literal analogy
Comparing TV’s rating system with the movie rating system

12. Create 5 analogies of your own!