PSC482G, Spring 2000
Answers
to Assignment 1
Critical thinking 1
Read:
The essays “Using important words precisely” and “Probability, belief, and
proof.”
Answer these
questions:
For “Important words”:
1. This brief essay describes two distinctly different meanings for fact. Use a good-sized dictionary and see how many other meanings or shadings of meaning you can find for this word. List each and put it into a sentence. Now do you see how careful we must be to speak and write precisely?
(All citations come from Webster’s New World Dictionary, Second College Edition, Simon and Schuster, 1984.)
a. A deed or act, especially a criminal act, as in accessory
after the fact.
b. A
thing that has actually happened or is really true. The hard facts of this case are¼
c. The
state of things as they are. Is your idea
fact or fancy?
d.
Something said to have occurred or supposed to be true. Check
your facts.
e. In
law, an actual or alleged incident or condition, as distinguished from
its legal consequence. Ladies and
gentlemen of the jury, I will show that my client was in fact nowhere near the
subway station at the time of the alleged crime.
2. Same as (1) except for prove.
a. To test by experiment or try out. The
proof of the pudding is in the eating.
b. To
establish as true. With his telescope,
Galileo proved the Copernican theory.
c. To
establish the validity or authenticity of. He
proved the disputed will genuine.
d. To
show oneself to be capable or dependable. He
proved himself up to the task.
e. Mathematics:
To test or verify the correctness of (a calculation, etc.). I
wish I had been the one to prove Fermat’s last theorem.
f. Printing:
To test via a trial run. I just received
the page proofs of my new article.
3. Another common word that is often misused is control. In each of the sentences below, explain what control or its derivative means. (You will probably need to consult your dictionary.)
a. One of the main techniques of scientific research is controlled
experiments. “Checked” experiments, in which the variable creating the
effect being investigated is identified by carefully changing one variable at a
time.
b.
I carefully controlled the conditions of my experiment. I made sure that my
experiment was run exactly as I wanted it to be run.
c.
He is the controller of the university. He regulates the university’s
financial affairs.
d.
Control your rage! Hold back your rage!
e.
When arriving in Brussels, turn left as you exit from Passport Control. The
place where passports are checked, not where they are regulated.
For “Probability, etc.”:
4. National polls of the American people consistently show that 80%–90% of them believe that a conspiracy killed John F. Kennedy. How does the careful thinker evaluate to this statement? Does it constitute sufficient grounds for reopening the official investigation, as some students of the assassination think? The careful thinker concludes that the fact that a great majority of people believe something implies little or nothing about whether it is actually true. It also says nothing about how deep this belief is. Thus opinions, even opinions of a great majority, should not be used to justify action like reopening an official investigation unless the opinions can be shown to be backed up by evidence. If you think that this constitutes an argument against democratic rule in every aspect of a society, you are right.
5. Evaluate this fictitious statement that is typical of advocacy groups: “If you believe with us that the rainforests must be saved, send a generous contribution to Save the Rainforests, P.O. Box 1234, Anywhere, U.S.A.” This appeal is fallacious because belief that the rain forests must be saved is not the same as proving that they must be saved.
6.“After deliberating for 16 hours spread over three days, the jury found the defendant guilty of embezzling $100,000 from the small post office where she worked.” What did the jury really do? The jury chose to believe that the defendant was guilty, based on evidence that was almost certainly less than conclusive.
7. Certain JFK-conspiracists are now saying “Conspiracy is now a fact. Let us move beyond Dealey Plaza to the deeper meanings of the assassination.” What sort of documentation should we expect from anyone who proposes this? Conclusive, objective evidence for conspiracy, not just a statement of a belief.
8. Person 1: “The Mafia killed Kennedy.” Person 2: “You’re crazy. It had nothing to do with it.” What is the logical weakness in this dialogue, and how could we alter it in order to bring meaning to it? The logical weakness is that both discussants are stating their conclusions (beliefs) rather than giving reasons for them. One cannot counter one conclusion with another. To improve the dialogue, the first person must give his reasons for his conclusion. If the second person disagrees with him, the latter must respond by showing why the first person is wrong and then stating his conclusion and the reason for it.
9. Why do I say “I don’t care a whit what you believe; I care only what you can prove”? Because believing is a subjective, individual act that demonstrates only the inclination of the person and implies nothing about the truth of the proposition in question. Anyone can believe anything. What counts is what you can prove (or better stated, the probability of the proposition’s being true.
10. What are the implications of convicting someone of murder and imposing the death sentence based on “beyond a reasonable doubt and to a moral certainty”? Because this “standard of proof” requires a probability of only about 90%–95% to convict, some 5%–10% of defendants convicted of murder will actually be innocent. Thus, a significant fraction of death penalties will be erroneous. In other words, innocent people will routinely be executed because the law accepts probability rather than certainty as its standard of proof. Under such circumstances, how can it be justifiable to retain the death penalty?