Analogies

Analogy – draw a conclusion about one thing on the basis of a comparison of that thing and another.

· Primary subject – Subject you want to draw a conclusion about

· Analogue – Analogous case

A priori Analogies – Used to support a decision to treat relevantly similar cases the same way (morally, legally, logically, or administratively). The analogous case needn’t be real.

Inductive Analogies – Used as a basis for prediction. The analogous cases must be real.

Cases of A priori Analogies

1) Martin Gardner, God as a Gardner

2) Judith Jarvis Thomson, Famous Violinist

Abortion Argument

P1) The fetus is a person.

P2) If the fetus is a person, then the fetus has a right to life.

L) Therefore, the fetus has a right to life.

P3) The fetus’s right to life outweighs the mother’s right to decide what happens to her body

P4) If (L) and (P3), then any act of abortion is wrong

C) Therefore, any act of abortion is wrong.

Thompson’s Parody

P1) The violinist is a person.

P2) If the violinist is a person, then the violinist has a right to life.

L) Therefore, the violinist has a right to life.

P3) The violinist’s right to life outweighs your right to decide what happens to your body.

P4) If (L) and (P3), then unplugging yourself from the violinist is morally wrong.

C) Therefore, unplugging yourself from the violinist is morally wrong..

To Evaluate A priori Analogies

1. Are the similarities real?

2. Are the similarities significant?

3. Are the similarities highlighted relevant to the point asserted in the conclusion?

4. To refute an analogy find differences that are negatively relevant to the conclusion.

To Evaluate Inductive Analogies

1. Are the similarities real?

2. Are the similarities significant?

3. Is the analogue real; are the facts genuine?

4. Are the similarities numerous (similarities cumulate)?

5. To refute an analogy find differences that are negatively relevant to the conclusion. Use background knowledge

Ronald Munson’s The Way of Words

“Suppose that by paying 250 dollars you could go into the largest and most exclusive department store in town and pick out and take home anything you could carry away with you. You would have access to the finest silks, precious jewels, handworked bracelets of gold and platinum, fabulous clothes by the best designers in the world. It would be foolish to the point of imbecility if you paid your money, walked I, and picked out a piece of bubble gum. Well, that’s what many college students do, in effect. They pay a nominal amount of money, and by doing so they gain access to some of the greatest treasures of the intellect in the world. Merely by asking, they can discover things that people labored for years to find out. Just by going to class, they can receive the outcome of years of thought and effort of the most outstanding thinkers and scientists the human race has produced. Do they take advantage of this? Often they do not. They merely want to know which courses are the easier ones, which don’t have to be taken, and what are the minimum requirements for graduation. For their money they are offered a fortune, but they choose a piece of mental bubble gum.”