Learning from Experience
1. Barack Obama won the 2012 presidential election held in the United States of America. If we ignore all the attitude changes before or after the election, and if we only consider the votes of individuals as evidence for the conclusion Most Americans prefer Mr. Obama to Mr. Romney, is this a weak or a strong induction?
2. Is the following induction very strong, strong, weak, or very weak?
‘The frequency of lung cancer in persons who have smoked a pack or more of cigarettes daily for a period of twenty years is eight times greater than it is for nonsmokers.
Therefore, smoking is dangerous to one's health.'
3. State which of the following must be the case if A is a necessary condition for B.
(a) Whenever A occurs, B occurs
(b) Whenever A fails to occur, B fails to occur
(c) Whenever B has occurred, A has occurred
(d) Whenever B fails to occur, A fails to occur
4. State what you believe to be necessary conditions for phenomena of the following types:
(a) being overweight
(b) a suntan
(c) suffocation
(d) being pregnant
5. State which of the following must be the case if A is a sufficient condition for B.
(a) Whenever A occurs, B occurs
(b) Whenever A fails to occur, B fails to occur
(c) Whenever B has occurred, A has occurred
(d) Whenever B fails to occur, A fails to occur
6. State what you believe to be sufficient conditions for phenomena of the following types.
(a) becoming a parent
(b) living
(c) being responsible
(d) relieving boredom
7. The following are analogical arguments that rest on implied generalization. State the generalization from which the conclusion is drawn and evaluate the strength of the analogy.
(a) There is only one head of the household, one leader of the pack, one captain of the ship, and one President of the United States. Therefore, there is only one God.
(b) Thinking creatures on the earth all have faces. And aliens, described or pictured in science fiction, all have faces of some kind of another. Everything that thinks has a face.
8. The following passages contain analogies. Distinguish those that contain analogical arguments from those that make non-argumentative use of analogy.
(a) The stock market is like a crazy roller-coaster ride. The index shoots up, then crashes, and then the whole thing starts again.
(b) The Universe is populated by billions of galaxies, all of which are receding from one another, like raisins in an expanding pudding.
(c) Just as a general moves miniature figures over a map before setting his troops in action, thinking is a kind of experimental configuration of energies. Thinking is a kind of planning.
(d) Parents motivate children to solve mathematical problems when they insist that homework gets finished and work with their kids to explain difficulties. It seems like they could also motivate children to solve emotional problems, even though there is little focus on this in the schools.
9. The following are attempted ‘refutations by analogy.' Evaluate the persuasiveness of the refutation.
(a) President Obama appointed Mr. McDonald, from Procter and Gamble, to head the Veterans' Administration, citing his expertise in business and his reputation as a ‘turn- around' specialist. He might as well have nominated the ice skater Nancy Kerrigan, who is also quite good at turning around.
(b) Pope Benedict XVI issued an injunction to Catholics prohibiting surrogate motherhood. But doesn't this put Mary in a difficult situation?
10. Which of Mill's methods apply to the following reasonings?
(a) The Greeks and the Jews both owe their writing systems to the Phoenicians. Compare the Greek alpha, beta, gamma, to the Hebrew aleph, beth, gimmel.
(b) If you apply yourself and persevere in your studies, you will earn a degree.
(c) The industrial might of the North was simply too strong for Lee's army. That's why the South lost the Civil War.
(d) "When all else fails, Watson, the impossible may well prove to be true."