Exercises 4-5
A. Underline the premises, circle the conclusions, and box any premise or
conclusion indicators in the following arguments. Note any cases where 'and',
'but' 'either' or 'or' are NOT used to join statements together.
*1. Holding in one's feelings is not healthy, since it might lead to
psychosomatic illness or it might result in anti?social behavior.
2. Computers cannot think; for, if something is a machine, then it cannot think.
3. Since 7 is greater than 5, it follows that 12 is greater than either 7 or 5.
4. Civilization has caused more harm than good to mankind because it not only
has given human beings the chance to be moral, but it has also made possible
immorality. And, the pernicious and cruel effects of immorality seems to far
outweigh the benefits of what little moral behavior there is.
5. If 'A' is greater than 'B' and 'B' is greater than 'C' then 'A' is greater
than 'C'. 'A' is greater than 'B' and 'B' is greater than 'C'. So, 'A' is
greater than 'C'.
6. If the Dodgers come in first, then the Reds will come in second. The Dodgers
will come in first. Therefore, the Reds will come in second.
*7. Either it will rain or it will snow. It will not snow. Therefore, it will
rain.
8. It has never snowed in June or July here, so it shouldn't snow this summer
either.
9. "It is plain that agriculture, by its very nature, must be the least
lucrative of all arts, because its products being of the most indispensable
necessity for all men, their price must be proportionate to the abilities of the
poorest." ??J.J. Rousseau, Discourse on the Origin of Inequality
10. Since human history is the story of one war after another, either there will
be more wars in the future or human nature will change.
*11. If the President is telling the truth then the Russians will not invade
Poland. The Russians will invade Poland. So, the President is lying.
*12. Either the Germans not will quit the United Nations or the moon will turn
to green cheese. Since the moon will not turn to green cheese, it follows that
the Germans will not quit the United Nations.
13. "Remembering, which occurs now, cannot...possibly prove that what is
remembered occurred at some other time, because the world might have sprung into
being five minutes ago, exactly as it then was, full of acts of remembering
which were entirely misleading." ??Bertrand Russell, An Outline of
Philosophy
14. All unhappiness is due to unsatisfied desires. All satisfaction is due to
satisfied desires. And, no one can satisfy all his or her desires. Therefore,
either one must give up desires and be happy or one must resign oneself to a
life of unhappiness. (This is a paraphrase of one of the teachings of the
Buddha, Siddhartha Gautama.)
Exercises 4-6
For each of the following, first determine if the passage contains an
argument. If it does, underline premises, circle conclusions, and box off any
premise or conclusion indicators. If the passage does not contain an argument,
put a check in the margin and indicate whether or not it contains a conditional
statement.
*1. There must be simple substances because there are composites; for a
composite is nothing else than a collection or aggregate of simple substances.
??Leibniz, Monadology
*2. "It is a test of true theories not only to account for but to predict
phenomena." --William Whewell, Philosophy of the Inductive Sciences,
aphorism 39.
*3. If the water is black, then the well is polluted.
*4. The water is black and the well is polluted.
5. "It is not enough to have a good mind. The main thing is to use it
well." --René Descartes, Discourse on Method
6. Since the water is black, the well is probably polluted.
7. The water is black; therefore, the well is polluted.
* 8. Memory should not be trusted as the sole judge of the truth of any claim,
since memory is fallible and memory sometimes is constituted by later acts.
9. Computers are extremely useful. I bought one last year and am glad I did.
10. "A man's conscience and his judgement is the same thing, and as the
judgement, so also the conscience, may be erroneous." --Thomas Hobbes
11. You ought to buy a computer because they're extremely useful.
12. I bought a computer; so, I must be smarter than you are.
*13. She did well on the exam; so, she'll probably graduate.
14. "If women do not put forth, finally, that effort to become all that
they have it in them to become, they will forfeit their own humanity."
Betty Friedan, The Feminine Mystique
15. Women should put forth their best effort. Actually, men should, too.
*16. If the world were to end today, could you say that your life had been worth
living?
17. "There must have been a burglary at my house because the place was a
shambles: drawers were open and papers were strewn all over the floor. And my
silver collection was gone."
18. If you are a defense attorney for someone you know is guilty, you must
nevertheless make the best defense possible for your client.
*19. "...[W]e ought mutually to tolerate one another, because we are all
weak, irrational, and subject to change and error." ??Voltaire,
"Toleration"
20. "The first man who, having fenced in a piece of land, said, 'This is
mine,' and found people naïve enough to believe him, that man was the true
founder of civil society." --Jean Jacques Rousseau
*21. If cows could talk, their gods would be bovine.
22. "Religion is the opium of the people." Who said that?
23. Since dogs have no free will, they should not be held morally responsible
for attacking or killing humans.
24. Dogs have no free will. They don't even know what 'moral' or 'immoral'
means.
*25. The drug problem is out of control. I don't know who is in charge of
solving this problem. If it get's much worse we'll be in too much trouble to do
anything about it.
26. Electrons do not exist because they cannot be seen or tasted or touched.
And, anything which cannot be seen, tasted or touched does not exist.
*27. There must be life on Mars since nobody has been able to prove there isn't
life there.
28. If the key works, I'll open the door.
29. The key didn't work. The door was locked. We left at 5:00 p.m.
30. Around here 'free speech' means 'free to say whatever you want as long as
you don't offend anyone.'