EXERCISES, QUESTIONS, AND ACTIVITIES My Answers

Transcription

1 EXERCISES, QUESTIONS, AND ACTIVITIES My Answers Exercises Argument Forms I For each of the following arguments, determine the form of the inference and decide whether or not the inference is valid. ). Jim isn t guilty. 2. If Jim were guilty then his fingerprints would be on the doorknob. 3. Jim s fingerprints aren t on the doorknob. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. Valid 2). George knows who did it. 2. If George knew who did it then he d be acting nervous. 3. George is acting nervous. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. Invalid If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P.

2 2 3). Keith didn t wear his lucky socks. 2. If Keith wears his lucky socks then he ll get the job. 3. Keith didn t get the job. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. Valid 4). Ellen committed the crime. 2. If Ellen didn t commit the crime then she d be willing to take a polygraph. 3. Ellen isn t willing to take a polygraph. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. Valid 5). Sara doesn t know who did it. 2. If Sara saw the crime then she d know who did it. 3. Sara didn t see the crime. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. Invalid If P then Q. Not Q. Therefore Not P.

3 3 6). Phil will get the job. 2. If Phil is the boss s nephew then he ll get the job. 3. Phil is the boss s nephew. If P then Q. P. Therefore Q. Valid If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. 7). John doesn t need a lawyer. 2. John isn t guilty. 3. If Jon is guilty then he needs a lawyer. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. Invalid If P then Q. Not Q. Therefore Not P. 8). Hank is the best candidate. 2. If Hank is the best candidate then he ll get the job. 3. Hank will the get the job. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. Invalid If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P.

4 4 9). Jack will get the job. 2. If Jack doesn t interview well then he won t get the job. 3. Jack does interview well. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. Invalid If P then Q. Not Q. Therefore Not P. 0). The police don t have an air-tight case. 2. The police haven t made an arrest. 3. If the police had an air-tight case then they d make an arrest. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. Valid ). Joan isn t hired. 2. Joan won t be happy. 3. If Joan isn t hired then she won t be happy. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. Invalid If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P.

5 5 2). Jane will get the job. 2. Mary won t be hired. 3. If Mary isn t hired then Jane will get the job. If P then Q. P. Therefore Q. Valid If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. 3). Ellen will need the loan. 2. Ellen isn t hired. 3. If Ellen is hired then she won t need the loan. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. Invalid If P then Q. Not Q. Therefore Not P. 4). Ann got the job. 2. Ann will take us out to dinner. 3. If Ann didn t get the job then she won t take us out to dinner. If P then Q. P. Therefore Q. If P then Q. Q. Therefore P. If P then Q. Not P. Therefore Not Q. If P then Q. Not Q. Therefore Not P. Valid

6 6 Argument Forms II )??? + The world is well-designed. God exists. What premise may we put in the empty box to make the inference valid? (There are two correct responses.) a. If the world is well-designed then God exists. b. If the world weren t well designed then God wouldn t exist. c. If God didn t exist then the world wouldn t be well-designed. d. If God did exist then the world would be well-designed. 2)??? + Stealing makes people unhappy. Stealing is ethically wrong. What premise may we put in the empty box to make the inference valid? (There are two correct responses.) a. If stealing makes people unhappy then stealing is ethically wrong. b. If stealing isn t ethically wrong then stealing doesn t make people unhappy. c. If stealing is ethically wrong then stealing makes people unhappy. d. If stealing doesn t make people unhappy then stealing isn t ethically wrong.

7 7 Argument Forms III ) You re having coffee with a large group of friends late one night when the conversation turns to God. Sandra says, Who can believe that God doesn t exist? Clearly he does! Most people have an innate sense of right and wrong, which is exactly what we would expect if God existed! (To say that something s innate is to say that you re born with it or will develop it naturally.) Sandra s argument may be diagrammed as follows.. God exists. 2. Most people have an innate sense of right and wrong. 3. If God existed then most people would have an innate sense of right and wrong. A What is the form of inference A in Sandra s argument, and is that inference valid or invalid? a) If P then Q + P Q b) If P then Q + Q Invalid P c) If P then Q + Not P Not Q d) If P then Q + Not Q Not P 2) Jane responds to Sandra by saying I don t think that works. Most people would have an innate sense of right and wrong even though God doesn t exist. Jane thinks that this disproves the premise If God existed then most people would have an innate sense of right and wrong. Does it disprove this premise? Rest the mouse over your answer. a) Yes b) No

8 8 3) George enters the discussion and says God doesn t exist. If there were good evidence for life after death then God would have to exist, but there isn t any such evidence. His argument runs:. God doesn t exist. 2. If there were good evidence for life after death then God would exist. 3. There isn t good evidence for life after death. A What is the form of inference A in George s argument, and is that inference valid or invalid? a) If P then Q + P Q b) If P then Q + Q P c) If P then Q + Not P Invalid Not Q d) If P then Q + Not Q Not P 4) Howard responds to George by saying I disagree. God doesn t exist even though there is good evidence for life after death. If this is true, would Howard have disproven the premise If there were good evidence for life after death then God would exist? Rest the mouse over your answer. a) Yes b) No

9 9 Argument Forms IV ) Consider the argument God doesn t approve of stealing. If God approves of stealing then stealing is ethically good. Therefore, stealing isn t ethically good. What is the form of this inference? If P then Q. Not P. Therefore Not Q. Is the inference in this argument valid or invalid? Invalid. 2) Which of the following situations would show the premise, If God approves of stealing then stealing is ethically good, to be false? a. God approves of stealing but it s ethically bad anyway. b. God approves of stealing and it s ethically good. c. God doesn t approve of stealing but it s ethically good anyway. d. God doesn t approve of stealing and it s ethically bad. 3) Consider the argument God doesn t exist because if God exists then there would be no suffering in the world, but there is suffering in the world. What is the form of this inference? If P then Q. Not Q. Therefore Not P. Is the inference in this argument valid or invalid? Valid. 4) Which of the following situations would show the premise If God exists then there would be no suffering in the world, to be false? Rest the mouse over your answer. Smoking a. God doesn t exist and there is evil and suffering in the world. b. God doesn t exist and there is no evil and suffering in the world. c. God exists and there is evil and suffering in the world. d. God exists and there is no evil and suffering in the world. ) Brenda started smoking because her friends smoked, because she thought it would relax her and because she believed that smoking would make her look more mature you know, the way smoke curls in the air and the way she could hold a cigarette between her first and second fingers, just like in the movies. This passage contains an explanation of why. 2) I think Brenda should quit smoking. It s a health risk. It sets a bad example for her kids. And given the fact that cigarettes are pretty expensive, she d save a lot of money if she didn t smoke. Without a doubt, she should kick the habit! Of course, I would never nag her about it.. Brenda should quit smoking. 2. Smoking is a health risk.

10 0 3. It sets a bad example for her kids. 4. Cigarettes are pretty expensive. 5. Brenda would save a lot of money if she didn t smoke ) We definitely shouldn t ban smoking on campus at UWSP! The purpose of a college education is to teach people to make their own decisions and a total ban on smoking will prevent people from deciding on their own whether or not they want to smoke. How can we teach people to make up their own minds if we re banning smoking? Besides, if we allow UWSP to ban smoking then we open the door to all sorts of other intrusions into our private lives since the decision to smoke is a personal one.. We definitely shouldn t ban smoking on campus at UWSP! 2. The purpose of a college education is to teach people to make their own decisions 3. A total ban on smoking will prevent people from deciding on their own whether or not they want to smoke. 4. If we allow UWSP to ban smoking then we open the door to all sorts of other intrusions into our private lives. 5. The decision to smoke is a personal one ) Smoking is clearly a threat to public health; through second-hand smoke, it harms everyone who happens to be around the smoker. Nobody can deny that smoking is a public health threat. Clearly, though, we shouldn t permit any public health threats on the campus. Besides, people on campus who want smoking to be banned outnumber people on campus who don t want smoking to be banned and the majority should rule. For these reasons and more, smoking should be banned in all indoor and outdoor areas on campus.. Smoking should be banned in all indoor and outdoor areas on campus. 2. Smoking is clearly a threat to public health. 3. Through second-hand smoke, smoking harms everyone who happen to be around the smoker. 4. We shouldn t permit any public health threats on the campus.

11 5. People on campus who want smoking to be banned outnumber people on campus who don t want smoking to be banned. 6. The majority should rule Science ) In science there are objective ways to settle disputes. If two physicists disagree about the existence of a certain subatomic particle, for instance, they can run experiments and see who s right. If two astronomers disagree about the composition of the atmosphere on Pluto, they can perform the necessary observations and settle the matter. If two chemists disagree about whether or not a certain substance is explosive, they can light a match to it and see. There are objective ways to settle disputes in science; because there are objective ways to resolve disputes in science, we have reason to believe that science tells us the objective truth about the world, and because science tells us the objective truth about the world, it s is the most important discipline.. Science is the most important discipline. 2. In science there are objective ways to settle disputes. 3. If two physicists disagree about the existence of a certain subatomic particle they can run experiments and see who s right. 4. If two astronomers disagree about the composition of the atmosphere on Pluto, they can perform the necessary observations and settle the matter. 5. If two chemists disagree about whether or not a certain substance is explosive, they can light a match to it and see. 6. We have reason to believe that science tells us the objective truth about the world ) How I hate those arrogant, smug and narrow-minded people who go around claiming that science is the most important subject around! The stupidity of the view boggles the mind! Many of the most important questions can t be answered scientifically. Can science tell us what s ethical and unethical? Can science tell us the meaning of life? Can science tell us whether or not God exists? Obviously, there are

12 2 many answers that science can t give us! And if that weren t bad enough, science is basically ruining the world! What brought us the nuclear bomb? What brought us germ warfare? What cultivated the technology that s polluting the earth?. Science isn t the most important subject around. 2. Many of the most important questions can t be answered scientifically. 3. Science can t tell us what s ethical and unethical. 4. Science can t tell us the meaning of life. 5. Science can t tell us whether or not God exists. 6. Science is ruining the world. 7. Science brought us the nuclear bomb. 8. Science brought us germ warfare. 9. Science cultivated the technology that s polluting the earth Evolution ) Creationism isn t right. It s got to be wrong. First of all, there s evidence supporting evolution. We can trace the natural evolution of some plants and animals through the fossil record and we can direct the evolution of some plants and animals through selective breeding. Evolution is backed up by good scientific evidence. Second, the Bible says that God exists, but the Bible is wrong about some things.. Creationism isn t right. 2. There s evidence supporting evolution. 3. We can trace the natural evolution of some plants and animals through the fossil record. 4. We can direct the evolution of some plants and animals through selective breeding. 5. The Bible says that God exists. 6. The Bible is wrong about some things ) If evolution is taught in public school, then creationism should be taught as well. We can t recreate evolution in a laboratory. We can t rewind the universe to see exactly how humans got here. We haven t found a continual chain of skeletal remains that link us to the apes. When you think about it like this, you can see that evolution is just a theory.

13 3 Creationism is a theory too. So both accounts of human origin are equally respectable and if one is taught in public school, the other should be, too.. If evolution is taught in public school, then creationism should be taught as well. 2. We can t recreate evolution in a laboratory. 3. We can t rewind the universe to see exactly how humans got here. 4. We haven t found a continual chain of skeletal remains that link us to the apes. 5. Evolution is just a theory. 6. Creationism is a theory. 7. Both accounts of human origin are equally respectable ) Some people are opposed to teaching evolution because they re afraid that belief in evolution would undermine religious faith. Some people are opposed to teaching creationism because they re afraid that it would put religion back in the classroom and violate the separation of church and state. Neither fear is justified. The Mind This passage contains an explanation of why. ) There a number of reasons to think that the mind and the brain have different properties. First, as Descartes has shown, it s possible to doubt the existence of your brain but it isn t possible to doubt the existence of your mind. No matter how hard you try, you can t doubt that you have a mind. Second, other people can know as much about your brain as you do but nobody will ever know as much about your mind as you do. You will always know more about your mind than anybody else does. Third, your brain, but not your mind, takes up space. As Leibniz has proven, however, if two things have different properties then they can can t be the same thing. That s why the mind is not the brain. They can t be the same thing.. The mind is not the same as the brain. 2. The mind and the brain have different properties. 3. It s possible to doubt the existence of your brain but it isn t possible to doubt the existence of your mind. 4. Other people can know as much about your brain as you do but you will always know more about your mind than anybody else does. 5. Your brain, but not your mind, takes up space. 6. If two things have different properties then they can can t be the same thing.

14 ) The mind and the brain must be the same thing. If the mind weren t the same as the brain then you couldn t affect the mind by affecting the brain, but clearly you can. Strokes can affect memory. Depression can be the result of neurochemical imbalances. Certain kinds of brain damage can induce personality change. Obviously, affecting the brain affects the mind and so the mind must be the same thing as the brain.. The mind and the brain must be the same thing. 2. If the mind weren t the same as the brain then you couldn t affect the mind by affecting the brain. 3. Clearly you can. 4. Strokes can affect memory. 5. Depression can be the result of neurochemical imbalances. 6. Certain kinds of brain damage can induce personality change ) Once upon a time, psychology was part of philosophy and the mind was considered to be nonphysical, something entirely out of the natural order of things and beyond the realm of science. In the late 800 s, psychology branched out on its own, and soon it was developing a conception of the mind that enabled it to be studied scientifically. At first the mind was identified with patterns of observable behavior. Now, the mind tends to be equated with the brain, or a function of the brain, sort of a computer program. This passage contains neither an argument nor an explanation of why. 4) Many people, at one time or another, have wondered about the nature of the mind, probably because we often identify ourselves with our minds. Our thoughts and desires seem to constitute our selves, and when we think that we can survive the death of our bodies, we re probably thinking in terms of our minds surviving the death of our bodies. Can this happen? Well clearly, if our minds can survive the death of our physical bodies then our minds are nonphysical. But if our minds were physical then they would have the same sorts of properties that physical things have, and in fact they don t have the same sorts of properties as physical things. Minds, for instance, don t take up space or weigh anything but physical things do. It follows, then, that minds are nonphysical. Thus, minds can survive the death of the body.

15 5. Minds can survive the death of the body. 2. If our minds can survive the death of our physical bodies then our minds are nonphysical. 3. If our minds were physical then they would have the same sorts of properties that physical things have. 4. Minds don t have the same sorts of properties as physical things. 5. Minds don t take up space or weigh anything. 6. Physical things do take up space and weigh something. 7. Minds are nonphysical A B C Note that inference B is valid. Note that inference C is invalid. Artificial Intelligence ) As computers get more and more sophisticated, we can expect speculation about artificial intelligence to increase. Already, some programs are so responsive that it s hard to believe they don t understand what you re doing, but still some troglodytes believe that computers will never be able to think. This is just silly. The human brain produces a mind, and if the human brain can produce a mind then an electronic brain may be able to produce a mind as well. Why say that the human brain can make a mind but that a computer brain can t? Besides, the claim that computers will never be able to think is a prediction that technology will be limited in a certain way, and most such claims have been false.. Computers will be able to think. 2. The human brain produces a mind. 3. If the human brain can produce a mind then an electronic brain may be able to produce a mind as well. 4. The claim that computers will never be able to think is a prediction that technology will be limited in a certain way. 5. Most such claims have been false

16 6 God s Existence For each of the following passages, determine if it contains an argument, an explanation of why, or neither. If a passage contains an argument, analyze and evaluate it. ) Does God exist? This is probably one of the most popular metaphysical questions of all time, because how we answer this question determines how we approach our life, other individuals, and the prospect of death. The ontological argument tries to prove that God exists through rational reflection alone. Unfortunately this argument doesn t work, but maybe there are other arguments that can prove the existence of God. Maybe we just need to do more than reflect on the nature of God in order to see that God exists. Maybe we need to actually experience the world. So, what do you think? Does God exist or not? Obviously, he does. Consider for a moment what the world and all of the things in it are like. The iris of human eye is especially designed to contract in the presence of light and to dilate in darkened conditions. Giraffes have long necks that enable them to eat the leaves of trees. Fish have gills that let them breathe in the water. Clearly, each one of these examples is enough to prove that the world is very well-designed. But now consider this: God s creating the world is a sufficient condition for such order in the world, because God is supposed to be all powerful, all knowing and all good and this means that he would do a good job at making whatever world he attempts! If the world weren t well designed then it wouldn t have been created by God, but it is well-designed. Clearly, then, God created the world, and since he created the world, he must exist. [For your information, this is the teleological argument for God s existence.]. God exists. 2. The iris of human eye is especially designed to contract in the presence of light and to dilate in the darkened conditions. 3. Giraffes have long necks that enable them to eat the leaves of trees. 4. Fish have gills that let them breathe in the water. 5. The world is very well-designed. 6. If God created the world then there would be such order in the world. 7. God is supposed to be all powerful, all knowing and all good. 8. God would do a good job at making whatever world he attempts. 9. God created the world. 7 D A B C E F 9 G

17 7 2) There are a number of reasons to show that God exists. First of all, everything must be caused by something else. Nothing can cause itself and so there s a chain of causes that either goes back forever or else ends in a first cause. But the series of causes can t go backwards forever. It s impossible that a series of causes to go infinitely back and so there has to be a first cause. If there s a first cause, though, it s got to be God. Besides, regardless of how things got started, everything is pretty well designed right now and things could be this way only if they were created by God. If God didn t create the world, it wouldn t be so well designed.. God exists. 2. Everything must be caused by something else. 3. There s a chain of causes that either goes back forever or else ends in a first cause. 4. The series of causes can t go backwards forever. 5. There has to be a first cause. 6. If there s a first cause, it s got to be God. 7. Everything is pretty well designed right now. 8. Things could be this way only if they were created by God Ethics ) According to some sources, it is illegal to imitate an animal in Miami, to watch a moose from an airplane in Alaska, to shave without a permit in Missouri, to possess a pair of pliers in Texas and, in Kansas, to drive a Buffalo in the street. In Kentucky, you re required by law to bathe at least once a year and, in Utah, you must grant birds the right-of-way on a public highway. (Information from Monday, August 5, 2002, 2:50 p.m.) I don t see this passage proving or explaining anything, so I d say that it s neither an argument nor an explanation of why 2) Some people don t think that ethical truths are objective, but they re wrong. Anyone can see that ethical truths are objective. Laws are objective aren t they? What s legal and what s illegal is an objective fact. If this weren t enough, people tend to agree about what s right and wrong. Certain things are recognized by everyone as good or bad. Finally, without an objective right and wrong, there could be no Heaven or Hell. Obviously, then, ethical truths are objective.

18 8 This passage is trying to convince us that there is an objective right and wrong, and so it contains an argument.. There is an objective right and wrong. 2. Laws are objective. 3. People tend to agree about what s right and wrong. 4. Without an objective right and wrong, there could be no Heaven or Hell A B C Are you feeling comfortable ignoring sentences that repeat ideas? The statement question Laws are objective, aren t they? and What s legal and what s illegal is an objective fact both convey the idea that laws are objective, so I just recorded that idea once. If this weren t enough, people tend to agree about what s right and wrong, and Certain things are recognized by everyone as good or bad, basically say the same thing too, so I just recorded that idea once as well. Also, could you see that ideas 2, 3 and 4 are all independent reasons for? To a certain extent, this is signaled by the If this weren t enough and Finally The best way to see this, though, is to note that these ideas don t really work together. Each of them is playing a slightly different game than the others. The first is talking about laws, the second about interpersonal agreement, and the third about the afterlife. When I look at this argument, the first thing that strikes me how bad left and right branches are. The fact that laws are objective doesn t show us that ethics are objective, and so inference A is weak. Inference C is even worse. Perhaps there could be no Heaven or Hell without an objective right and wrong, but who says that there is a Heaven or Hell? The only branch of this argument that I might take seriously is the middle one, so that s where most of my attention goes. Is the premise that people tend to agree about what s right and wrong both true and acceptable to the argument s audience? Since it s clear from the passage that 3 only intends to claim that some moral judgments are shared by virtually everyone, I think we can say that this is true. As far as I know, practically everyone thinks that torturing and murdering innocent people for sport is wrong. Furthermore, I think it s fair to expect the argument s audience to accept 3, so I d say that premise 3 is okay. Now, what about the inference from 3 to? If Bob believed that people tend to agree about some moral judgments, how likely will he be to believe that there is an objective right and wrong? It seems to me that he d be pretty likely. to believe this. Although there are other reasons why an opinion might be unanimous, barring evidence of collusion or threat, it s probably fair to assume that a unanimous opinion is grounded in an objective fact that almost everyone sees. Consequently, I d say that inference C is relatively strong. And so, thanks to its sound middle branch, the entire argument is good.

19 A B C 3) Historically, religion has fostered belief in Hell because, in a world still dominated by religious authority, it prevented some people from doing wrong, comforted those who saw evil-doers prosper and, of course, reinforced the power of the Church. This passage is accounting for why religion has encouraged belief in Hell, under the assumption that we already believe this, and so this is an explanation of why, not an argument. 4) Something is ethically good if it maximizes happiness and what maximizes happiness is culturally independent. Besides, we don t excuse another culture s bad behavior, which we would have to do if cultural relativism were true. Cultural relativism just can t be right! Does this passage try to convince us that something is true? Yes. It tries to prove that cultural relativism is wrong, making it an argument.. Cultural relativism is wrong. 2. Something is good if it maximizes happiness. 3. What maximizes happiness is culturally independent. 4. We don t excuse another culture s bad behavior. 5. We would have to excuse another culture s bad behavior if cultural relativism were true A B Here, I m hoping that you were able to correctly group ideas 2 and 3 and ideas 4 and 5 into two independent lines of reasoning. Remember to look for common themes. The theme of the left-hand branch is maximizing happiness and the them of the right-hand branch is the bad behavior of other cultures. Also, could you see that 2 and 3 are dependent reasons and that 4 and 5 are dependent reasons, each pair connected with a bracket and a plus sign? If you had difficulty, I ll bet you put one or more of these pairs into a premise / subconclusion relationship, having an arrow going from 2 to 3, or from 5 to 4, for instance. That s a pretty common mistake. Remember to double-check your inferences, though, and you ll

20 20 nip those errors in the bud. Something is good if it maximizes happiness. Therefore what maximizes happiness is culturally independent, for example, doesn t really make much sense, when you think about it. Neither does We would have to excuse another culture s bad behavior if cultural relativism were true. Therefore we don t excuse another culture s bad behavior. The first thing I notice about the left-hand branch of this argument is premise 2. Although it may be true that something is good it if maximizes happiness, I don t think it s something that we can expect the argument s audience to take for granted. Accordingly, 2 is a bad premise. Perhaps it could be transformed into a decent subconclusion, but as it stands, the left line of reasoning is bad. The right-hand side of the argument is a bit more interesting to me. The inference is fine because belief in 4 and 5 would practically compel belief in. Premise 4 is probably okay; in fact we do condemn other cultures for various reasons. One could argue that premise 4 assumes the conclusion since it presupposes that another culture s behavior can be bad, but maybe all it means by bad is behavior that we don t like. Premise 5, however, is a bit confusing. As we saw in our evaluation of the argument in passage, cultural relativism would allow us to criticize what another culture does, provided we re explicit about the fact that we re leveling that criticism from the ethical point of view defined by our own culture and are not implying that this point of view is in any objective sense better than the ethical stance defined by the culture we re criticizing and according to which that culture s behavior is perfectly fine. Of course, that would be a rather weak sort of criticism, but it might be enough to undercut the claim that cultural relativism would force us to excuse whatever another culture does. I m inclined to say, then, that premise 5 is bad, and, in consequence, maintain that the argument fails as a whole A B 5) The philosophical position which links ethical right to the maximization of happiness is known as utilitarianism. It stands in contrast to deontological ethics, which equates morality with the doing of ones duty, and both utilitarianism and deontology are opposed to various relativistic ethics. This passage simply tells us what utilitarianism and deontology are. It doesn t account for why something is the case and it doesn t try to convince us of anything. Accordingly, it s neither an explanation of why nor an argument.

21 2 6) The reason that Janice and Cynthia are no longer friends is the that they had a terrible fight over the morality of animal testing. Janice, who s father is undergoing treatment for cancer, believes that it s sometimes justified to test drugs and other medical procedures on animals. Cynthia, a strong advocate for animal rights, violently disagrees. This passage accounts for why something is the case. In particular, it accounts for why Janice and Cynthia are no longer friends, making it an explanation of why. 7) Some people think that ethics is just a matter of opinion, that if two people disagree about whether something s good or bad, neither one of them is really right or wrong. What do you think? People don t fight about matters of opinion, but people clearly do fight about ethics, don t they? People fight about ethics all the time. Ethics can t be just a matter of opinion! Besides, morality is grounded in biology, isn t it? You just need to remember that morality concerns the well-being of living things, to see that. And of course, nothing that s grounded in a science can be just a matter of opinion.. Ethics isn t just a matter of opinion. 2. People don t fight about matters of opinion. 3. People do fight about ethics. 4. Morality is grounded in biology. 5. Morality concerns the well-being of living things. 6. Nothing that s grounded in science can be just a matter of opinion. 5 B C A To correctly diagram this argument, you need to recognize when two sentences express the same idea ( [P]eople clearly do fight about ethics, don t they? and People fight about ethics all the time, say the same thing.), see that the argument has two independent lines of reasoning (one about fighting and one about science), and correctly distinguish between dependent reasons and ideas in a premise / subconclusion relationship. Good job, if you got this one right on the first try! Looking at the left-hand branch of this argument, I must say that I think premise 2 is false. Although people might not fight about things that they recognize to be matters of opinion, it seems to me that people are sometimes inclined to mistake opinion for fact and to fight about the former believing themselves to be fighting about the latter. Think about matters of taste, for instance. People battle about the appropriate shade of paint for the living room and the attractiveness of body-piercing, when, in actuality, there might not be an objective right and wrong about such questions. I, therefore, judge the left-hand branch to be weak.

22 22. Ethics isn t just a matter of opinion. 2. People don t fight about matters of opinion. 3. People do fight about ethics. 4. Morality is grounded in biology. 5. Morality concerns the well-being of living things. 6. Nothing that s grounded in science can be just a matter of opinion. 5 B C A Turning my attention to the right-hand branch, I m unconvinced by inference B. Surely Bob could believe that morality concerns the well-being of living things without believing that morality is grounded in biology. Perhaps Bob believes that all living things have spiritual souls and that ethics stems from the proper care of these souls, rather than from any biological facts. In conclusion, then, I decide that this entire argument is bad.. Ethics isn t just a matter of opinion. 2. People don t fight about matters of opinion. 3. People do fight about ethics. 4. Morality is grounded in biology. 5. Morality concerns the well-being of living things. 6. Nothing that s grounded in science can be just a matter of opinion. 5 B C A 8) Human infants require care because they are born incapable of fending for themselves and for a number of years remain unable to survive on their own. The infants of many other animal species are able to provide for themselves after a very short period of time, if not immediately. This passage assumes that we already know human infants require care and confines itself to explaining why this is so, making it an explanation of why. 9) Although some ethical opinions are nothing more than expressions of personal likes and dislikes, other moral facts must be independent of any individual. This is due to the

23 23 fact that certain moral norms are necessary for the functioning of a society. For instance, human infants are helpless and require a significant amount of care. Accordingly, any culture which didn t require adults to care for the young would eventually go extinct. Similarly, any culture of moderate complexity requires communication; hence, any culture must have some truth-telling rule if it s to survive. Again, no culture could exist without trust; trust couldn t exist if there were no general prohibitions against murder and so every culture must place some moral restrictions on killing. A society couldn t function without certain basic moral rules. Passage inspired by James Rachels, The Challenge of Cultural Relativism, (Steven M. Cahn, Patricia Kitcher, George Sher and Peter Markie, eds., Reason at Work: Introductory Readings in Philosophy, third edition., pp , reprinted from The Elements of Moral Philosophy, Second Edition by James Rachels, 993.). Some moral facts must be independent of any individual. 2. Certain moral norms are necessary for the functioning of a society. 3. Human infants are helpless and require a significant amount of care. 4. Any culture which didn t require adults to care for the young would eventually go extinct. 5. Any culture of moderate complexity requires communication. 6. Any culture must have some truth-telling rule if it s to survive. 7. No culture could exist without trust. 8. Trust couldn t exist if there were no general prohibitions against murder. 9. Every culture must place some moral restrictions on killing A C E D B 2 F G This argument is differs from the previous three in that it offers only one line of reasoning for the ultimate conclusion: specifically, the claim expressed in idea 2 that certain moral norms are necessary for the survival of society. Idea 2 itself, however, is a subconclusion, and I saw three lines of reason in its support: the discussion about child care in ideas 3 and 4, the claims about lying in ideas 5 and 6, and the bit about trust in ideas 7, 8 and 9. After seeing that, it was only a matter of figuring out exactly how these groups of ideas should go together. To see that 3 was offered as a reason to believe 4, I used accordingly, which functions as an inference indicator expression in the passage. To see that 5 was offered as a reason to believe 6, I used the inference indicator word hence. The relationship between 7, 8 and 9 was a bit trickier to discern. I started by realizing that the so told me that 8 was a reason for 9; then I used the Puzzle Piece Method to see that 8 needed to work with 7 to get 9, joining together at the notion of trust to give us an idea composed of the notions culture and murder.

24 24 Premise 3 is both true and acceptable to the audience of the argument, I think. Furthermore, it seems to me that anyone who believed 3 would be strongly inclined to believe 4, that anyone who believed 4 would believe 2 as well, and that anyone who believed 2 would be lead to believe. In other words, premise 3 and inferences A, B, and G are all strong, giving us a dependable path to the conclusion and making the entire argument good. If I wanted to, of course, I could examine the rest of the argument, but it isn t necessary and I may consider myself finished.. Some moral facts must be independent of any individual. 2. Certain moral norms are necessary for the functioning of a society. 3. Human infants are helpless and require a significant amount of care. 4. Any culture which didn t require adults to care for the young would eventually go extinct. 5. Any culture of moderate complexity requires communication. 6. Any culture must have some truth-telling rule if it s to survive. 7. No culture could exist without trust. 8. Trust couldn t exist if there were no general prohibitions against murder. 9. Every culture must place some moral restrictions on killing A C E D B 2 F G 0) Murder is often understood to involve the unjustified taking of a human life and is commonly distinguished from the more generic and neutral concept of killing. Although some killing, such as that done in war-time for self-defense or the defense of others, may be permissible or even laudatory, murder, as such, never is. This passage elucidates the difference between murder and killing without trying to explain or argue for anything and so it s neither an explanation of why nor an argument. ) If ethics were objective then ethical facts would be a type of scientific fact, right? If ethics were objective then ethical facts would exist independently of what we happen to think of them, and scientific facts exist independently of our opinion. But ethical facts aren t a type of scientific fact because we can t derive an ought from an is. Furthermore, in view of the fact that if ethics were objective then ethical facts would exist independently of what we happen to think of them, if ethics were objective, ethical facts wouldn t depend upon us. Ethical facts do depend upon us, though. Doesn t ethics have to do with human beings?. Ethics aren t objective. 2. If ethics were objective then ethical facts would be a type of scientific fact.

25 25 3. If ethics were objective then ethical facts would exist independently of what we happen to think of them. 4. Scientific facts exist independently of our opinion. 5. Ethical facts aren t a type of scientific fact. 6. We can t derive an ought from an is. 7. If ethics were objective, ethical facts wouldn t depend upon us. 8. Ethical facts do depend upon us. 9. Ethics has to do with human beings A B D E C F Personally, I think this is a challenging argument! The first thing I did was ask how many lines of reasoning it had, and I saw two: one about scientific fact and one about dependence on human beings. The furthermore helped me out with this. Discovering the relationships between ideas 3, 4, 6 and 5 was a nontrivial matter, mostly because there was only one inference indicator expression to help me: the because between ideas 5 and 6. The Puzzle Piece Method helped me to see that 2 was supported by 3 and 4 together, and once I saw that I could see that 2 and 5 worked together to give me. So much for the left-hand branch of the argument. When attacking the right-hand branch, I noticed that idea 3 was used again. In view of the fact that told me that 3 was giving us 7. The connection between 8 and 9 was less obvious. Basically, I used the fact that when people follow a claim with a rhetorical question, the idea implied in the question is sometimes intended as support for the preceding claim. Besides, it made sense to think of 9 as supporting 8. Once I had 3 going to 7 and 9 going to 8, I used the Puzzle Piece Test to see that 7 and 8 are dependent reasons for. And if you were able to get that one on your own, you should feel very proud! Letting myself survey the left side of this argument as a whole, I notice that idea 2 makes me uncomfortable. At first, I m not even sure why. It just doesn t sit right. Since 2 is a subconclusion, I look above it. Is premise 3 okay? Yes. Existing independently of our opinion is part of what we mean when we say that a fact is objective. Furthermore, I think that premise 4 is fine as well. Most, if not all, scientific facts appear to exist independently of what we happen to think of them; that s why we speak of scientific discoveries you can t discover something unless it s already there. So, I feel okay about ideas 3 and 4, but I don t feel okay about idea 2. This tells me that there might be something wrong with inference A. I ll see if I can use the counterexample method to figure out what it is. Here are the ideas:

26 26 2. If ethics were objective then ethical facts would be a type of scientific fact. 3. If ethics were objective then ethical facts would exist independently of what we happen to think of them. 4. Scientific facts exist independently of our opinion Can I uniformly replace key words or phrases in these ideas in such a way that 3 and 4 are clearly true but 2 is clearly false? To help keep things straight, I ll color the key words and phrases. 2. If ethics were objective then ethical facts would be a type of scientific fact. 3. If ethics were objective then ethical facts would exist independently of what we happen to think of them. 4. Scientific facts exist independently of our opinion. After thinking a bit (and this does take a little thought and practice) I decide to replace ethics with Ann s pet, objective with carnivorous, exist independently of our opinion with eat meat, and scientific fact with mutant man-eating shark. This gives me the following: 2. If Ann s pet were carnivorous then Ann s pet would be a type of mutant man-eating shark. 3. If Ann s pet were carnivorous then Ann s pet would eat meat. 4. Mutant man-eating sharks eat meat. Although it s true that if Ann s pet were carnivorous then Ann s pet would eat meat, and although it s true that mutant man-eating sharks eat meat, it certainly doesn t follow that if Ann s pet were carnivorous then Ann s pet would be a type of mutant man-eating shark. And why not? Because there are lots of carnivorous animals besides mutant man-eating sharks and Ann s pet could be one of those! This objection shows that the inference from 3 and 4 to 2 is bad. Okay, now let s see what this objection would be like when leveled at our original inference. I ll re-replace carnivorous animals with objective facts mutant man-eating shark with scientific fact and Ann s pet with ethics. This gives me There are lots of objective facts besides scientific facts and ethical facts could be one of those. Does this help to explain why I can feel comfortable with 3 and 4 but uncomfortable with 2? Yes! Although I believe that if ethics were objective then ethical facts would exist independently of what we happen to think of them, and although I believe that scientific facts exist independently of our opinion, I don t believe that if ethics were objective then ethical facts would be a type of scientific fact because I m prepared to admit that there

27 27 are objective facts that aren t scientific facts and think that ethical facts might be among them. Good! My initial discomfort with 2 has be vindicated. The problem is with inference A.. Ethics aren t objective. 2. If ethics were objective then ethical facts would be a type of scientific fact. 3. If ethics were objective then ethical facts would exist independently of what we happen to think of them. 4. Scientific facts exist independently of our opinion. 5. Ethical facts aren t a type of scientific fact. 6. We can t derive an ought from an is. 7. If ethics were objective, ethical facts wouldn t depend upon us. 8. Ethical facts do depend upon us. 9. Ethics has to do with human beings A B D E C F Now what about the other line of reasoning? I m not that keen on inference D. It s true, I think, that if ethics were objective then ethical facts would exist independently of what we happen to think of them, but I don t think it follows that if ethics were objective then they wouldn t depend upon us. It s one thing to exist independently of what we happen to think, and so to be independent of our opinion, and quite another to not depend on us at all. The biological facts of human reproduction, for instance, don t depend upon our opinions. We can believe in the stork all we want to, and babies won t be made that way. Nonetheless, the facts of human reproduction do depend upon us somehow, in the sense that if we didn t exist then there would be humans for the facts to be about. Because I (and Bob) could believe 3 without believing 7, inference D is bad. Because inference D is bad, the right-hand branch of the argument is bad. And because all other branches were bad as well, the argument as a whole is bad.. Ethics aren t objective. 2. If ethics were objective then ethical facts would be a type of scientific fact. 3. If ethics were objective then ethical facts would exist independently of what we happen to think of them. 4. Scientific facts exist independently of our opinion. 5. Ethical facts aren t a type of scientific fact. 6. We can t derive an ought from an is. 7. If ethics were objective, ethical facts wouldn t depend upon us. 8. Ethical facts do depend upon us. 9. Ethics has to do with human beings.

28 A B D E C F Capital Punishment ) The death penalty has enjoyed a boom in popularity recently. Wisconsin, though, still isn t a death penalty state. This passage contains neither an argument nor an explanation of why. 2) We should have the death penalty. It has the potential to be an effective deterrent, it s sanctioned by the Bible, and it satisfies the human desire for revenge.. We should have the death penalty. 2. The death penalty has the potential to be an effective deterrent. 3. The death penalty is sanctioned by the Bible. 4. The death penalty satisfies the human desire for revenge ) We should abolish the death penalty in the United States. It s is cruel and unusual punishment and we shouldn t practice cruel and unusual punishment. Besides that, most civilized nations disapprove of the death penalty. Without a doubt, we should get rid of it.. The death penalty should be abolished. 2. The death penalty is cruel and unusual punishment. 3. We shouldn t practice cruel and unusual punishment. 4. Most civilized nations disapprove of the death penalty. 4 Real Life ) Answers will vary. Construction

29 29 ) I think that the theme of the current line of reasoning is something like adjusting to college.. All freshmen should live in residence halls. 2. Living in residence halls helps students adjust to college. 3. Living in residence halls enables students to network with other students. 4. Networking with others students helps students adjust to college. 5. Freshmen should do whatever helps them adjust to college A B 2) Obviously, there are many different additional themes that could be added. Since the first line of reasoning focuses on the students well-being, a completely different kind of reasoning might focus on the well-being of the college. 3) I might begin that line of reasoning as follows:. All freshmen should live in residence halls. 2. Living in residence halls helps students adjust to college. 3. Living in residence halls enables students to network with other students. 4. Networking with others students helps students adjust to college. 5. Freshmen should do whatever helps them adjust to college. 6. The college makes quite a bit of money from residence hall fees A C B 4) We could write up the passage like this: Living in residence halls helps students adjust to college since it enables students to network with other students and since this networking helps students adjust to college. Given that living in residence halls helps students adjust to college, however, and given that freshmen should do whatever helps them adjust to college, all freshmen should live in residence halls. And there s another reason why all freshmen should live in residence halls: the college makes quite a bit of money from residence hall fees. 5) Answers will vary.